Systems and methods of initiating a power shutdown mode for a surgical instrument

ABSTRACT

Various systems and methods of controlling a surgical instrument are disclosed. In one aspect, the surgical instrument includes an end effector that is pivotable between an unarticulated position and an articulated position, a knife bar movable between an unfired position and a fired position. The surgical instrument is configured to determine a firing state according to whether the knife bar is moving between the unfired position and the fired position, determine an articulation state according to whether the displacement member is moving between the first position and the second position, and then initiate a power shutdown mode according to the firing state and the articulation state.

TECHNICAL FIELD

The present disclosure relates to surgical instruments and, in variouscircumstances, to surgical stapling and cutting instruments that aredesigned to cut and staple tissue.

BACKGROUND

In a surgical stapling and cutting instrument it may be useful tocontrol the display and other components of the instrument to providealerts to the clinician using the instrument, power down the instrument,and take other such actions according to the operational state of thesurgical instrument. The operational state of the surgical instrument(i.e., whether the instrument is cutting, stapling, clamping,articulating, or taking other such actions) can be detected by one ormore sensors, which can be communicably coupled to a control circuitconfigured to execute various processes according to the states of theinstrument detected by the sensors. In some situations, it may be usefulto provide alerts to the clinician in order to alert the clinician as toerrors experienced by the surgical instrument. In other situations, itmay be useful to power down the instrument when the instrument hascompleted its surgical stapling and cutting operations. In still othersituations, it may be useful to display the position of the knife duringthe course of a firing stroke thereof in order to allow a clinician toview the cutting progress.

SUMMARY

In one aspect, a surgical instrument comprising: an end effectorpivotable between an unarticulated position and an articulated position;a displacement member coupled to the end effector, the displacementmember movable between a first position and a second position to drivethe end effector between the unarticulated position and the articulatedposition; a knife bar movable between a unfired position and a firedposition; a control circuit configured to: determine a firing stateaccording to whether the knife bar is moving between the unfiredposition and the fired position; determine an articulation stateaccording to whether the displacement member is moving between the firstposition and the second position; and initiate a power shutdown modeaccording to the firing state and the articulation state.

In another aspect, a surgical instrument comprising: an end effectorpivotable from an articulation home position; a knife bar movable from aknife home position; and a control circuit configured to: determinewhether the knife bar is moving; determine whether the end effector ismoving; and initiate a power shutdown mode upon the knife bar and theend effector not moving.

In another aspect, a method of controlling a surgical instrumentcomprising an end effector, a displacement member coupled to the endeffector, the displacement member movable between a first position and asecond position, and a knife bar movable between a unfired position anda fired position, the method comprising: determining a firing stateaccording to whether the knife bar is moving between the unfiredposition and the fired position; determining an articulation stateaccording to whether the displacement member is moving between the firstposition and the second position; and initiating a power shutdown modeaccording to the firing state and the articulation state.

FIGURES

The novel features of the aspects described herein are set forth withparticularity in the appended claims. These aspects, however, both as toorganization and methods of operation may be better understood byreference to the following description, taken in conjunction with theaccompanying drawings.

FIG. 1 is a perspective view of a surgical instrument that has aninterchangeable shaft assembly operably coupled thereto according to oneaspect of this disclosure.

FIG. 2 is an exploded assembly view of a portion of the surgicalinstrument of FIG. 1 according to one aspect of this disclosure.

FIG. 3 is an exploded assembly view of portions of the interchangeableshaft assembly according to one aspect of this disclosure.

FIG. 4 is an exploded view of an end effector of the surgical instrumentof FIG. 1 according to one aspect of this disclosure.

FIGS. 5A-5B is a block diagram of a control circuit of the surgicalinstrument of FIG. 1 spanning two drawing sheets according to one aspectof this disclosure.

FIG. 6 is a block diagram of the control circuit of the surgicalinstrument of FIG. 1 illustrating interfaces between the handleassembly, the power assembly, and the handle assembly and theinterchangeable shaft assembly according to one aspect of thisdisclosure.

FIG. 7 illustrates a control circuit configured to control aspects ofthe surgical instrument of FIG. 1 according to one aspect of thisdisclosure.

FIG. 8 illustrates a combinational logic circuit configured to controlaspects of the surgical instrument of FIG. 1 according to one aspect ofthis disclosure.

FIG. 9 illustrates a sequential logic circuit configured to controlaspects of the surgical instrument of FIG. 1 according to one aspect ofthis disclosure.

FIG. 10 is a diagram of an absolute positioning system of the surgicalinstrument of FIG. 1 where the absolute positioning system comprises acontrolled motor drive circuit arrangement comprising a sensorarrangement according to one aspect of this disclosure.

FIG. 11 is an exploded perspective view of the sensor arrangement for anabsolute positioning system showing a control circuit board assembly andthe relative alignment of the elements of the sensor arrangementaccording to one aspect of this disclosure.

FIG. 12 is a diagram of a position sensor comprising a magnetic rotaryabsolute positioning system according to one aspect of this disclosure.

FIG. 13 is a section view of an end effector of the surgical instrumentof FIG. 1 showing a firing member stroke relative to tissue graspedwithin the end effector according to one aspect of this disclosure.

FIG. 14 illustrates a block diagram of a surgical instrument programmedto control distal translation of a displacement member according to oneaspect of this disclosure.

FIG. 15 illustrates a diagram plotting two example displacement memberstrokes executed according to one aspect of this disclosure.

FIG. 16 is a partial perspective view of a portion of an end effector ofa surgical instrument showing an elongate shaft assembly in anunarticulated orientation with portions thereof omitted for clarity,according to one aspect of this disclosure.

FIG. 17 is another perspective view of the end effector of FIG. 16showing the elongate shaft assembly an unarticulated orientation,according to one aspect of this disclosure.

FIG. 18 is an exploded assembly perspective view of the end effector ofFIG. 16 showing the elongate shaft assembly aspect, according to oneaspect of this disclosure.

FIG. 19 is a top view of the end effector of FIG. 16 showing theelongate shaft assembly in an unarticulated orientation, according toone aspect of this disclosure.

FIG. 20 is another top view of the end effector of FIG. 16 showing theelongate shaft assembly in a first articulated orientation, according toone aspect of this disclosure.

FIG. 21 is another top view of the end effector of FIG. 16 showing theelongate shaft assembly in a second articulated orientation, accordingto one aspect of this disclosure.

FIG. 22 is a perspective view of a surgical system including a handleassembly coupled to an interchangeable surgical tool assembly that isconfigured to be used in connection with conventional surgicalstaple/fastener cartridges and radio frequency (RF) cartridges accordingto one aspect of this disclosure.

FIG. 23 is an exploded perspective assembly view of the surgical systemof FIG. 22 according to one aspect of this disclosure.

FIG. 24 is a top cross-sectional view of a portion of theinterchangeable surgical tool assembly of FIG. 22 with the end effectorthereof in an articulated position according to one aspect of thisdisclosure.

FIG. 25 is a perspective view of an onboard circuit board arrangementand RF generator plus configuration according to one aspect of thisdisclosure.

FIG. 26 illustrates a logic flow diagram of a process of determiningwhen to initiate a low power shutdown of the surgical instrumentaccording to one aspect of this disclosure.

FIG. 27 illustrates a front view of a display screen or portion thereofshowing an image indicating that the surgical instrument is in a lowpower shutdown mode according to one aspect of this disclosure.

DESCRIPTION

Applicant of the present application owns the following patentapplications that were filed on Sep. 29, 2017 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 15/720,800, entitled SYSTEMS ANDMETHODS FOR PROVIDING ALERTS ACCORDING TO THE OPERATIONAL STATE OF ASURGICAL INSTRUMENT, by inventors Richard L. Leimbach et al., filed Sep.29, 2017, now U.S. Patent Application Publication No. 2019/0099178.

U.S. patent application Ser. No. 15/720,811, entitled SYSTEMS ANDMETHODS OF DISPLAYING A KNIFE POSITION FOR A SURGICAL INSTRUMENT, byinventors Richard L. Leimbach et al., filed Sep. 29, 2017, now U.S.Patent Application Publication No. 2019/0102930.

U.S. patent application Ser. No. 15/720,838, entitled SYSTEMS ANDMETHODS FOR LANGUAGE SELECTION OF A SURGICAL INSTRUMENT, by inventorsRichard L. Leimbach et al., filed Sep. 29, 2017, now U.S. PatentApplication Publication No. 2019/0099224.

U.S. Design patent application Ser. No. 29/619,956, entitled DISPLAYSCREEN OR PORTION THEREOF WITH ANIMATED GRAPHICAL USER INTERFACE, byinventors Tony C. Siebel et al., filed Sep. 29, 2017.

U.S. Design patent application Ser. No. 29/619,600, entitled DISPLAYSCREEN OR PORTION THEREOF WITH ANIMATED GRAPHICAL USER INTERFACE, byinventors Tony C. Siebel et al., filed Sep. 29, 2017.

U.S. Design patent application Ser. No. 29/619,609, entitled DISPLAYSCREEN OR PORTION THEREOF WITH ANIMATED GRAPHICAL USER INTERFACE, byinventors Tony C. Siebel et al., filed Sep. 29, 2017.

U.S. Design patent application Ser. No. 29/619,624, entitled DISPLAYSCREEN OR PORTION THEREOF WITH ANIMATED GRAPHICAL USER INTERFACE, byinventors Tony C. Siebel et al., filed Sep. 29, 2017.

U.S. patent application Ser. No. 15/720,852, entitled SYSTEM AND METHODSFOR CONTROLLING A DISPLAY OF A SURGICAL INSTRUMENT, by inventors RichardL. Leimbach et al., filed Sep. 29, 2017, now U.S. Patent ApplicationPublication No. 2019/0099180.

Certain aspects are shown and described to provide an understanding ofthe structure, function, manufacture, and use of the disclosed devicesand methods. Features shown or described in one example may be combinedwith features of other examples and modifications and variations arewithin the scope of this disclosure.

The terms “proximal” and “distal” are relative to a clinicianmanipulating the handle of the surgical instrument where “proximal”refers to the portion closer to the clinician and “distal” refers to theportion located further from the clinician. For expediency, spatialterms “vertical,” “horizontal,” “up,” and “down” used with respect tothe drawings are not intended to be limiting and/or absolute, becausesurgical instruments can used in many orientations and positions.

Example devices and methods are provided for performing laparoscopic andminimally invasive surgical procedures. Such devices and methods,however, can be used in other surgical procedures and applicationsincluding open surgical procedures, for example. The surgicalinstruments can be inserted into a through a natural orifice or throughan incision or puncture hole formed in tissue. The working portions orend effector portions of the instruments can be inserted directly intothe body or through an access device that has a working channel throughwhich the end effector and elongated shaft of the surgical instrumentcan be advanced.

In some aspects, surgical instruments can include devices capable ofperforming cutting (as in, e.g., FIGS. 1 and 22), stapling (as in, e.g.,FIG. 1), electrosurgical (as in, e.g., FIG. 22), and/or ultrasonicoperations, as described in further detail below. Further detailregarding ultrasonic surgical instruments can be found in U.S. Pat. No.6,283,981, entitled METHOD OF BALANCING ASYMMETRIC ULTRASONIC SURGICALBLADES; U.S. Pat. No. 6,309,400, entitled CURVED ULTRASONIC WAVEGUIDEHAVING A TRAPEZOIDAL CROSS SECTION; and U.S. Pat. No. 6,436,115,entitled BALANCED ULTRASONIC WAVEGUIDE INCLUDING A PLURALITY OF BALANCEASYMMETRIES, the entire disclosures of which are hereby incorporatedherein by reference.

FIGS. 1-4 depict a motor-driven surgical instrument 10 for cutting andfastening that may or may not be reused. In the illustrated examples,the surgical instrument 10 includes a housing 12 that comprises a handleassembly 14 that is configured to be grasped, manipulated, and actuatedby the clinician. The housing 12 is configured for operable attachmentto an interchangeable shaft assembly 200 that has an end effector 300operably coupled thereto that is configured to perform one or moresurgical tasks or procedures. In accordance with the present disclosure,various forms of interchangeable shaft assemblies may be effectivelyemployed in connection with robotically controlled surgical systems. Theterm “housing” may encompass a housing or similar portion of a roboticsystem that houses or otherwise operably supports at least one drivesystem configured to generate and apply at least one control motion thatcould be used to actuate interchangeable shaft assemblies. The term“frame” may refer to a portion of a handheld surgical instrument. Theterm “frame” also may represent a portion of a robotically controlledsurgical instrument and/or a portion of the robotic system that may beused to operably control a surgical instrument. Interchangeable shaftassemblies may be employed with various robotic systems, instruments,components, and methods disclosed in U.S. Pat. No. 9,072,535, entitledSURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENTARRANGEMENTS, which is hereby incorporated herein by reference in itsentirety.

FIG. 1 is a perspective view of a surgical instrument 10 that has aninterchangeable shaft assembly 200 operably coupled thereto according toone aspect of this disclosure. The housing 12 includes an end effector300 that comprises a surgical cutting and fastening device configured tooperably support a surgical staple cartridge 304 therein. The housing 12may be configured for use in connection with interchangeable shaftassemblies that include end effectors that are adapted to supportdifferent sizes and types of staple cartridges, have different shaftlengths, sizes, and types. The housing 12 may be employed with a varietyof interchangeable shaft assemblies, including assemblies configured toapply other motions and forms of energy such as, radio frequency (RF)energy, ultrasonic energy, and/or motion to end effector arrangementsadapted for use in connection with various surgical applications andprocedures. The end effectors, shaft assemblies, handles, surgicalinstruments, and/or surgical instrument systems can utilize any suitablefastener, or fasteners, to fasten tissue. For instance, a fastenercartridge comprising a plurality of fasteners removably stored thereincan be removably inserted into and/or attached to the end effector of ashaft assembly.

The handle assembly 14 may comprise a pair of interconnectable handlehousing segments 16, 18 interconnected by screws, snap features,adhesive, etc. The handle housing segments 16, 18 cooperate to form apistol grip portion 19 that can be gripped and manipulated by theclinician. The handle assembly 14 operably supports a plurality of drivesystems configured to generate and apply control motions tocorresponding portions of the interchangeable shaft assembly that isoperably attached thereto. A display may be provided below a cover 45.

FIG. 2 is an exploded assembly view of a portion of the surgicalinstrument 10 of FIG. 1 according to one aspect of this disclosure. Thehandle assembly 14 may include a frame 20 that operably supports aplurality of drive systems. The frame 20 can operably support a closuredrive system 30, which can apply closing and opening motions to theinterchangeable shaft assembly 200. The closure drive system 30 mayinclude an actuator such as a closure trigger 32 pivotally supported bythe frame 20. The closure trigger 32 is pivotally coupled to the handleassembly 14 by a pivot pin 33 to enable the closure trigger 32 to bemanipulated by a clinician. When the clinician grips the pistol gripportion 19 of the handle assembly 14, the closure trigger 32 can pivotfrom a starting or “unactuated” position to an “actuated” position andmore particularly to a fully compressed or fully actuated position.

The handle assembly 14 and the frame 20 may operably support a firingdrive system 80 configured to apply firing motions to correspondingportions of the interchangeable shaft assembly attached thereto. Thefiring drive system 80 may employ an electric motor 82 located in thepistol grip portion 19 of the handle assembly 14. The electric motor 82may be a DC brushed motor having a maximum rotational speed ofapproximately 25,000 RPM, for example. In other arrangements, the motormay include a brushless motor, a cordless motor, a synchronous motor, astepper motor, or any other suitable electric motor. The electric motor82 may be powered by a power source 90 that may comprise a removablepower pack 92. The removable power pack 92 may comprise a proximalhousing portion 94 configured to attach to a distal housing portion 96.The proximal housing portion 94 and the distal housing portion 96 areconfigured to operably support a plurality of batteries 98 therein.Batteries 98 may each comprise, for example, a Lithium Ion (LI) or othersuitable battery. The distal housing portion 96 is configured forremovable operable attachment to a control circuit board 100, which isoperably coupled to the electric motor 82. Several batteries 98connected in series may power the surgical instrument 10. The powersource 90 may be replaceable and/or rechargeable. A display 43, which islocated below the cover 45, is electrically coupled to the controlcircuit board 100. The cover 45 may be removed to expose the display 43.

The electric motor 82 can include a rotatable shaft (not shown) thatoperably interfaces with a gear reducer assembly 84 mounted in meshingengagement with a with a set, or rack, of drive teeth 122 on alongitudinally movable drive member 120. The longitudinally movabledrive member 120 has a rack of drive teeth 122 formed thereon formeshing engagement with a corresponding drive gear 86 of the gearreducer assembly 84.

In use, a voltage polarity provided by the power source 90 can operatethe electric motor 82 in a clockwise direction wherein the voltagepolarity applied to the electric motor by the battery can be reversed inorder to operate the electric motor 82 in a counter-clockwise direction.When the electric motor 82 is rotated in one direction, thelongitudinally movable drive member 120 will be axially driven in thedistal direction “DD.” When the electric motor 82 is driven in theopposite rotary direction, the longitudinally movable drive member 120will be axially driven in a proximal direction “PD.” The handle assembly14 can include a switch that can be configured to reverse the polarityapplied to the electric motor 82 by the power source 90. The handleassembly 14 may include a sensor configured to detect the position ofthe longitudinally movable drive member 120 and/or the direction inwhich the longitudinally movable drive member 120 is being moved.

Actuation of the electric motor 82 can be controlled by a firing trigger130 that is pivotally supported on the handle assembly 14. The firingtrigger 130 may be pivoted between an unactuated position and anactuated position.

Turning back to FIG. 1, the interchangeable shaft assembly 200 includesan end effector 300 comprising an elongated channel 302 configured tooperably support a surgical staple cartridge 304 therein. The endeffector 300 may include an anvil 306 that is pivotally supportedrelative to the elongated channel 302. The interchangeable shaftassembly 200 may include an articulation joint 270. Construction andoperation of the end effector 300 and the articulation joint 270 are setforth in U.S. Patent Application Publication No. 2014/0263541, entitledARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, whichis hereby incorporated herein by reference in its entirety. Theinterchangeable shaft assembly 200 may include a proximal housing ornozzle 201 comprised of nozzle portions 202, 203. The interchangeableshaft assembly 200 may include a closure tube 260 extending along ashaft axis SA that can be utilized to close and/or open the anvil 306 ofthe end effector 300.

Turning back to FIG. 1, the closure tube 260 is translated distally(direction “DD”) to close the anvil 306, for example, in response to theactuation of the closure trigger 32 in the manner described in theaforementioned reference U.S. Patent Application Publication No.2014/0263541. The anvil 306 is opened by proximally translating theclosure tube 260. In the anvil-open position, the closure tube 260 ismoved to its proximal position.

FIG. 3 is another exploded assembly view of portions of theinterchangeable shaft assembly 200 according to one aspect of thisdisclosure. The interchangeable shaft assembly 200 may include a firingmember 220 supported for axial travel within the spine 210. The firingmember 220 includes an intermediate firing shaft 222 configured toattach to a distal cutting portion or knife bar 280. The intermediatefiring shaft 222 may include a longitudinal slot 223 in a distal endconfigured to receive a tab 284 on the proximal end 282 of the knife bar280. The longitudinal slot 223 and the proximal end 282 may beconfigured to permit relative movement there between and can comprise aslip joint 286. The slip joint 286 can permit the intermediate firingshaft 222 of the firing member 220 to articulate the end effector 300about the articulation joint 270 without moving, or at leastsubstantially moving, the knife bar 280. Once the end effector 300 hasbeen suitably oriented, the intermediate firing shaft 222 can beadvanced distally until a proximal sidewall of the longitudinal slot 223contacts the tab 284 to advance the knife bar 280 and fire the staplecartridge positioned within the elongated channel 302. The spine 210 hasan elongated opening or window 213 therein to facilitate assembly andinsertion of the intermediate firing shaft 222 into the spine 210. Oncethe intermediate firing shaft 222 has been inserted therein, a top framesegment 215 may be engaged with the shaft frame 212 to enclose theintermediate firing shaft 222 and knife bar 280 therein. Operation ofthe firing member 220 may be found in U.S. Patent ApplicationPublication No. 2014/0263541. A spine 210 can be configured to slidablysupport a firing member 220 and the closure tube 260 that extends aroundthe spine 210. The spine 210 may slidably support an articulation driver230.

The interchangeable shaft assembly 200 can include a clutch assembly 400configured to selectively and releasably couple the articulation driver230 to the firing member 220. The clutch assembly 400 includes a lockcollar, or lock sleeve 402, positioned around the firing member 220wherein the lock sleeve 402 can be rotated between an engaged positionin which the lock sleeve 402 couples the articulation driver 230 to thefiring member 220 and a disengaged position in which the articulationdriver 230 is not operably coupled to the firing member 220. When thelock sleeve 402 is in the engaged position, distal movement of thefiring member 220 can move the articulation driver 230 distally and,correspondingly, proximal movement of the firing member 220 can move thearticulation driver 230 proximally. When the lock sleeve 402 is in thedisengaged position, movement of the firing member 220 is nottransmitted to the articulation driver 230 and, as a result, the firingmember 220 can move independently of the articulation driver 230. Thenozzle 201 may be employed to operably engage and disengage thearticulation drive system with the firing drive system in the variousmanners described in U.S. Patent Application Publication No.2014/0263541.

The interchangeable shaft assembly 200 can comprise a slip ring assembly600 which can be configured to conduct electrical power to and/or fromthe end effector 300 and/or communicate signals to and/or from the endeffector 300, for example. The slip ring assembly 600 can comprise aproximal connector flange 604 and a distal connector flange 601positioned within a slot defined in the nozzle portions 202, 203. Theproximal connector flange 604 can comprise a first face and the distalconnector flange 601 can comprise a second face positioned adjacent toand movable relative to the first face. The distal connector flange 601can rotate relative to the proximal connector flange 604 about the shaftaxis SA-SA (FIG. 1). The proximal connector flange 604 can comprise aplurality of concentric, or at least substantially concentric,conductors 602 defined in the first face thereof. A connector 607 can bemounted on the proximal side of the distal connector flange 601 and mayhave a plurality of contacts wherein each contact corresponds to and isin electrical contact with one of the conductors 602. Such anarrangement permits relative rotation between the proximal connectorflange 604 and the distal connector flange 601 while maintainingelectrical contact there between. The proximal connector flange 604 caninclude an electrical connector 606 that can place the conductors 602 insignal communication with a shaft circuit board, for example. In atleast one instance, a wiring harness comprising a plurality ofconductors can extend between the electrical connector 606 and the shaftcircuit board. The electrical connector 606 may extend proximallythrough a connector opening defined in the chassis mounting flange.Further details regarding slip ring assembly 600 may be found in U.S.Patent Application Publication No. 2014/0263541.

The interchangeable shaft assembly 200 can include a proximal portionfixably mounted to the handle assembly 14 and a distal portion that isrotatable about a longitudinal axis. The rotatable distal shaft portioncan be rotated relative to the proximal portion about the slip ringassembly 600. The distal connector flange 601 of the slip ring assembly600 can be positioned within the rotatable distal shaft portion.

FIG. 4 is an exploded view of one aspect of an end effector 300 of thesurgical instrument 10 of FIG. 1 according to one aspect of thisdisclosure. The end effector 300 may include the anvil 306 and thesurgical staple cartridge 304. The anvil 306 may be coupled to anelongated channel 302. Apertures 199 can be defined in the elongatedchannel 302 to receive pins 152 extending from the anvil 306 to allowthe anvil 306 to pivot from an open position to a closed positionrelative to the elongated channel 302 and surgical staple cartridge 304.A firing bar 172 is configured to longitudinally translate into the endeffector 300. The firing bar 172 may be constructed from one solidsection, or may include a laminate material comprising a stack of steelplates. The firing bar 172 comprises an I-beam 178 and a cutting edge182 at a distal end thereof. A distally projecting end of the firing bar172 can be attached to the I-beam 178 to assist in spacing the anvil 306from a surgical staple cartridge 304 positioned in the elongated channel302 when the anvil 306 is in a closed position. The I-beam 178 mayinclude a sharpened cutting edge 182 to sever tissue as the I-beam 178is advanced distally by the firing bar 172. In operation, the I-beam 178may, or fire, the surgical staple cartridge 304. The surgical staplecartridge 304 can include a molded cartridge body 194 that holds aplurality of staples 191 resting upon staple drivers 192 withinrespective upwardly open staple cavities 195. A wedge sled 190 is drivendistally by the I-beam 178, sliding upon a cartridge tray 196 of thesurgical staple cartridge 304. The wedge sled 190 upwardly cams thestaple drivers 192 to force out the staples 191 into deforming contactwith the anvil 306 while the cutting edge 182 of the I-beam 178 seversclamped tissue.

The I-beam 178 can include upper pins 180 that engage the anvil 306during firing. The I-beam 178 may include middle pins 184 and a bottomfoot 186 to engage portions of the cartridge body 194, cartridge tray196, and elongated channel 302. When a surgical staple cartridge 304 ispositioned within the elongated channel 302, a slot 193 defined in thecartridge body 194 can be aligned with a longitudinal slot 197 definedin the cartridge tray 196 and a slot 189 defined in the elongatedchannel 302. In use, the I-beam 178 can slide through the alignedlongitudinal slots 193, 197, and 189 wherein, as indicated in FIG. 4,the bottom foot 186 of the I-beam 178 can engage a groove running alongthe bottom surface of elongated channel 302 along the length of slot189, the middle pins 184 can engage the top surfaces of cartridge tray196 along the length of longitudinal slot 197, and the upper pins 180can engage the anvil 306. The I-beam 178 can space, or limit therelative movement between, the anvil 306 and the surgical staplecartridge 304 as the firing bar 172 is advanced distally to fire thestaples from the surgical staple cartridge 304 and/or incise the tissuecaptured between the anvil 306 and the surgical staple cartridge 304.The firing bar 172 and the I-beam 178 can be retracted proximallyallowing the anvil 306 to be opened to release the two stapled andsevered tissue portions.

FIGS. 5A-5B is a block diagram of a control circuit 700 of the surgicalinstrument 10 of FIG. 1 spanning two drawing sheets according to oneaspect of this disclosure. Referring primarily to FIGS. 5A-5B, a handleassembly 702 may include a motor 714 which can be controlled by a motordriver 715 and can be employed by the firing system of the surgicalinstrument 10. In various forms, the motor 714 may be a DC brusheddriving motor having a maximum rotational speed of approximately 25,000RPM. In other arrangements, the motor 714 may include a brushless motor,a cordless motor, a synchronous motor, a stepper motor, or any othersuitable electric motor. The motor driver 715 may comprise an H-bridgedriver comprising field-effect transistors (FETs) 719, for example. Themotor 714 can be powered by the power assembly 706 releasably mounted tothe handle assembly 14 for supplying control power to the surgicalinstrument 10. The power assembly 706 may comprise a battery which mayinclude a number of battery cells connected in series that can be usedas the power source to power the surgical instrument 10. In certaincircumstances, the battery cells of the power assembly 706 may bereplaceable and/or rechargeable. In at least one example, the batterycells can be Lithium-Ion batteries which can be separably couplable tothe power assembly 706.

The shaft assembly 704 may include a shaft assembly controller 722 whichcan communicate with a safety controller and power management controller716 through an interface while the shaft assembly 704 and the powerassembly 706 are coupled to the handle assembly 702. For example, theinterface may comprise a first interface portion 725 which may includeone or more electric connectors for coupling engagement withcorresponding shaft assembly electric connectors and a second interfaceportion 727 which may include one or more electric connectors forcoupling engagement with corresponding power assembly electricconnectors to permit electrical communication between the shaft assemblycontroller 722 and the power management controller 716 while the shaftassembly 704 and the power assembly 706 are coupled to the handleassembly 702. One or more communication signals can be transmittedthrough the interface to communicate one or more of the powerrequirements of the attached interchangeable shaft assembly 704 to thepower management controller 716. In response, the power managementcontroller may modulate the power output of the battery of the powerassembly 706, as described below in greater detail, in accordance withthe power requirements of the attached shaft assembly 704. Theconnectors may comprise switches which can be activated after mechanicalcoupling engagement of the handle assembly 702 to the shaft assembly 704and/or to the power assembly 706 to allow electrical communicationbetween the shaft assembly controller 722 and the power managementcontroller 716.

The interface can facilitate transmission of the one or morecommunication signals between the power management controller 716 andthe shaft assembly controller 722 by routing such communication signalsthrough a main controller 717 residing in the handle assembly 702, forexample. In other circumstances, the interface can facilitate a directline of communication between the power management controller 716 andthe shaft assembly controller 722 through the handle assembly 702 whilethe shaft assembly 704 and the power assembly 706 are coupled to thehandle assembly 702.

The main controller 717 may be any single core or multicore processorsuch as those known under the trade name ARM Cortex by TexasInstruments. In one aspect, the main controller 717 may be anLM4F230H5QR ARM Cortex-M4F Processor Core, available from TexasInstruments, for example, comprising on-chip memory of 256 KBsingle-cycle flash memory, or other non-volatile memory, up to 40 MHz, aprefetch buffer to improve performance above 40 MHz, a 32 KBsingle-cycle serial random access memory (SRAM), internal read-onlymemory (ROM) loaded with StellarisWare® software, 2 KB electricallyerasable programmable read-only memory (EEPROM), one or more pulse widthmodulation (PWM) modules, one or more quadrature encoder inputs (QEI)analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12analog input channels, details of which are available for the productdatasheet.

The safety controller may be a safety controller platform comprising twocontroller-based families such as TMS570 and RM4x known under the tradename Hercules ARM Cortex R4, also by Texas Instruments. The safetycontroller may be configured specifically for IEC 61508 and ISO 26262safety critical applications, among others, to provide advancedintegrated safety features while delivering scalable performance,connectivity, and memory options.

The power assembly 706 may include a power management circuit which maycomprise the power management controller 716, a power modulator 738, anda current sense circuit 736. The power management circuit can beconfigured to modulate power output of the battery based on the powerrequirements of the shaft assembly 704 while the shaft assembly 704 andthe power assembly 706 are coupled to the handle assembly 702. The powermanagement controller 716 can be programmed to control the powermodulator 738 of the power output of the power assembly 706 and thecurrent sense circuit 736 can be employed to monitor power output of thepower assembly 706 to provide feedback to the power managementcontroller 716 about the power output of the battery so that the powermanagement controller 716 may adjust the power output of the powerassembly 706 to maintain a desired output. The power managementcontroller 716 and/or the shaft assembly controller 722 each maycomprise one or more processors and/or memory units which may store anumber of software modules.

The surgical instrument 10 (FIGS. 1-4) may comprise an output device 742which may include devices for providing a sensory feedback to a user.Such devices may comprise, for example, visual feedback devices (e.g.,an LCD display screen, LED indicators), audio feedback devices (e.g., aspeaker, a buzzer) or tactile feedback devices (e.g., haptic actuators).In certain circumstances, the output device 742 may comprise a display743 which may be included in the handle assembly 702. The shaft assemblycontroller 722 and/or the power management controller 716 can providefeedback to a user of the surgical instrument 10 through the outputdevice 742. The interface can be configured to connect the shaftassembly controller 722 and/or the power management controller 716 tothe output device 742. The output device 742 can instead be integratedwith the power assembly 706. In such circumstances, communicationbetween the output device 742 and the shaft assembly controller 722 maybe accomplished through the interface while the shaft assembly 704 iscoupled to the handle assembly 702.

The control circuit 700 comprises circuit segments configured to controloperations of the powered surgical instrument 10. A safety controllersegment (Segment 1) comprises a safety controller and the maincontroller 717 segment (Segment 2). The safety controller and/or themain controller 717 are configured to interact with one or moreadditional circuit segments such as an acceleration segment, a displaysegment, a shaft segment, an encoder segment, a motor segment, and apower segment. Each of the circuit segments may be coupled to the safetycontroller and/or the main controller 717. The main controller 717 isalso coupled to a flash memory. The main controller 717 also comprises aserial communication interface. The main controller 717 comprises aplurality of inputs coupled to, for example, one or more circuitsegments, a battery, and/or a plurality of switches. The segmentedcircuit may be implemented by any suitable circuit, such as, forexample, a printed circuit board assembly (PCBA) within the poweredsurgical instrument 10. It should be understood that the term processoras used herein includes any microprocessor, processors, controller,controllers, or other basic computing device that incorporates thefunctions of a computer's central processing unit (CPU) on an integratedcircuit or at most a few integrated circuits. The main controller 717 isa multipurpose, programmable device that accepts digital data as input,processes it according to instructions stored in its memory, andprovides results as output. It is an example of sequential digitallogic, as it has internal memory. The control circuit 700 can beconfigured to implement one or more of the processes described herein.

The acceleration segment (Segment 3) comprises an accelerometer. Theaccelerometer is configured to detect movement or acceleration of thepowered surgical instrument 10. Input from the accelerometer may be usedto transition to and from a sleep mode, identify an orientation of thepowered surgical instrument, and/or identify when the surgicalinstrument has been dropped. In some examples, the acceleration segmentis coupled to the safety controller and/or the main controller 717.

The display segment (Segment 4) comprises a display connector coupled tothe main controller 717. The display connector couples the maincontroller 717 to a display through one or more integrated circuitdrivers of the display. The integrated circuit drivers of the displaymay be integrated with the display and/or may be located separately fromthe display. The display may comprise any suitable display, such as, forexample, an organic light-emitting diode (OLED) display, aliquid-crystal display (LCD), and/or any other suitable display. In someexamples, the display segment is coupled to the safety controller.

The shaft segment (Segment 5) comprises controls for an interchangeableshaft assembly 200 (FIGS. 1 and 3) coupled to the surgical instrument 10(FIGS. 1-4) and/or one or more controls for an end effector 300 coupledto the interchangeable shaft assembly 200. The shaft segment comprises ashaft connector configured to couple the main controller 717 to a shaftPCBA. The shaft PCBA comprises a low-power microcontroller with aferroelectric random access memory (FRAM), an articulation switch, ashaft release Hall effect switch, and a shaft PCBA EEPROM. The shaftPCBA EEPROM comprises one or more parameters, routines, and/or programsspecific to the interchangeable shaft assembly 200 and/or the shaftPCBA. The shaft PCBA may be coupled to the interchangeable shaftassembly 200 and/or integral with the surgical instrument 10. In someexamples, the shaft segment comprises a second shaft EEPROM. The secondshaft EEPROM comprises a plurality of algorithms, routines, parameters,and/or other data corresponding to one or more shaft assemblies 200and/or end effectors 300 that may be interfaced with the poweredsurgical instrument 10.

The position encoder segment (Segment 6) comprises one or more magneticangle rotary position encoders. The one or more magnetic angle rotaryposition encoders are configured to identify the rotational position ofthe motor 714, an interchangeable shaft assembly 200 (FIGS. 1 and 3),and/or an end effector 300 of the surgical instrument 10 (FIGS. 1-4). Insome examples, the magnetic angle rotary position encoders may becoupled to the safety controller and/or the main controller 717.

The motor circuit segment (Segment 7) comprises a motor 714 configuredto control movements of the powered surgical instrument 10 (FIGS. 1-4).The motor 714 is coupled to the main controller 717 by an H-bridgedriver comprising one or more H-bridge field-effect transistors (FETs)and a motor controller. The H-bridge driver is also coupled to thesafety controller. A motor current sensor is coupled in series with themotor to measure the current draw of the motor. The motor current sensoris in signal communication with the main controller 717 and/or thesafety controller. In some examples, the motor 714 is coupled to a motorelectromagnetic interference (EMI) filter.

The motor controller controls a first motor flag and a second motor flagto indicate the status and position of the motor 714 to the maincontroller 717. The main controller 717 provides a pulse-widthmodulation (PWM) high signal, a PWM low signal, a direction signal, asynchronize signal, and a motor reset signal to the motor controllerthrough a buffer. The power segment is configured to provide a segmentvoltage to each of the circuit segments.

The power segment (Segment 8) comprises a battery coupled to the safetycontroller, the main controller 717, and additional circuit segments.The battery is coupled to the segmented circuit by a battery connectorand a current sensor. The current sensor is configured to measure thetotal current draw of the segmented circuit. In some examples, one ormore voltage converters are configured to provide predetermined voltagevalues to one or more circuit segments. For example, in some examples,the segmented circuit may comprise 3.3V voltage converters and/or 5Vvoltage converters. A boost converter is configured to provide a boostvoltage up to a predetermined amount, such as, for example, up to 13V.The boost converter is configured to provide additional voltage and/orcurrent during power intensive operations and prevent brownout orlow-power conditions.

A plurality of switches are coupled to the safety controller and/or themain controller 717. The switches may be configured to controloperations of the surgical instrument 10 (FIGS. 1-4), of the segmentedcircuit, and/or indicate a status of the surgical instrument 10. Abail-out door switch and Hall effect switch for bailout are configuredto indicate the status of a bail-out door. A plurality of articulationswitches, such as, for example, a left side articulation left switch, aleft side articulation right switch, a left side articulation centerswitch, a right side articulation left switch, a right side articulationright switch, and a right side articulation center switch are configuredto control articulation of an interchangeable shaft assembly 200 (FIGS.1 and 3) and/or the end effector 300 (FIGS. 1 and 4). A left sidereverse switch and a right side reverse switch are coupled to the maincontroller 717. The left side switches comprising the left sidearticulation left switch, the left side articulation right switch, theleft side articulation center switch, and the left side reverse switchare coupled to the main controller 717 by a left flex connector. Theright side switches comprising the right side articulation left switch,the right side articulation right switch, the right side articulationcenter switch, and the right side reverse switch are coupled to the maincontroller 717 by a right flex connector. A firing switch, a clamprelease switch, and a shaft engaged switch are coupled to the maincontroller 717.

Any suitable mechanical, electromechanical, or solid state switches maybe employed to implement the plurality of switches, in any combination.For example, the switches may be limit switches operated by the motionof components associated with the surgical instrument 10 (FIGS. 1-4) orthe presence of an object. Such switches may be employed to controlvarious functions associated with the surgical instrument 10. A limitswitch is an electromechanical device that consists of an actuatormechanically linked to a set of contacts. When an object comes intocontact with the actuator, the device operates the contacts to make orbreak an electrical connection. Limit switches are used in a variety ofapplications and environments because of their ruggedness, ease ofinstallation, and reliability of operation. They can determine thepresence or absence, passing, positioning, and end of travel of anobject. In other implementations, the switches may be solid stateswitches that operate under the influence of a magnetic field such asHall-effect devices, magneto-resistive (MR) devices, giantmagneto-resistive (GMR) devices, magnetometers, among others. In otherimplementations, the switches may be solid state switches that operateunder the influence of light, such as optical sensors, infrared sensors,ultraviolet sensors, among others. Still, the switches may be solidstate devices such as transistors (e.g., FET, Junction-FET, metal-oxidesemiconductor-FET (MOSFET), bipolar, and the like). Other switches mayinclude wireless switches, ultrasonic switches, accelerometers, inertialsensors, among others.

FIG. 6 is another block diagram of the control circuit 700 of thesurgical instrument of FIG. 1 illustrating interfaces between the handleassembly 702 and the power assembly 706 and between the handle assembly702 and the interchangeable shaft assembly 704 according to one aspectof this disclosure. The handle assembly 702 may comprise a maincontroller 717, a shaft assembly connector 726 and a power assemblyconnector 730. The power assembly 706 may include a power assemblyconnector 732, a power management circuit 734 that may comprise thepower management controller 716, a power modulator 738, and a currentsense circuit 736. The power assembly connectors 730, 732 form aninterface 727. The power management circuit 734 can be configured tomodulate power output of the battery 707 based on the power requirementsof the interchangeable shaft assembly 704 while the interchangeableshaft assembly 704 and the power assembly 706 are coupled to the handleassembly 702. The power management controller 716 can be programmed tocontrol the power modulator 738 of the power output of the powerassembly 706 and the current sense circuit 736 can be employed tomonitor power output of the power assembly 706 to provide feedback tothe power management controller 716 about the power output of thebattery 707 so that the power management controller 716 may adjust thepower output of the power assembly 706 to maintain a desired output. Theshaft assembly 704 comprises a shaft assembly controller 722 coupled toa non-volatile memory 721 and shaft assembly connector 728 toelectrically couple the shaft assembly 704 to the handle assembly 702.The shaft assembly connectors 726, 728 form interface 725. The maincontroller 717, the shaft assembly controller 722, and/or the powermanagement controller 716 can be configured to implement one or more ofthe processes described herein.

The surgical instrument 10 (FIGS. 1-4) may comprise an output device 742to a sensory feedback to a user. Such devices may comprise visualfeedback devices (e.g., an LCD display screen, LED indicators), audiofeedback devices (e.g., a speaker, a buzzer), or tactile feedbackdevices (e.g., haptic actuators). In certain circumstances, the outputdevice 742 may comprise a display 743 that may be included in the handleassembly 702. The shaft assembly controller 722 and/or the powermanagement controller 716 can provide feedback to a user of the surgicalinstrument 10 through the output device 742. The interface 727 can beconfigured to connect the shaft assembly controller 722 and/or the powermanagement controller 716 to the output device 742. The output device742 can be integrated with the power assembly 706. Communication betweenthe output device 742 and the shaft assembly controller 722 may beaccomplished through the interface 725 while the interchangeable shaftassembly 704 is coupled to the handle assembly 702. Having described acontrol circuit 700 (FIGS. 5A-5B and 6) for controlling the operation ofthe surgical instrument 10 (FIGS. 1-4), the disclosure now turns tovarious configurations of the surgical instrument 10 (FIGS. 1-4) andcontrol circuit 700.

FIG. 7 illustrates a control circuit 800 configured to control aspectsof the surgical instrument 10 (FIGS. 1-4) according to one aspect ofthis disclosure. The control circuit 800 can be configured to implementvarious processes described herein. The control circuit 800 may comprisea controller comprising one or more processors 802 (e.g.,microprocessor, microcontroller) coupled to at least one memory circuit804. The memory circuit 804 stores machine executable instructions thatwhen executed by the processor 802, cause the processor 802 to executemachine instructions to implement various processes described herein.The processor 802 may be any one of a number of single or multi-coreprocessors known in the art. The memory circuit 804 may comprisevolatile and non-volatile storage media. The processor 802 may includean instruction processing unit 806 and an arithmetic unit 808. Theinstruction processing unit may be configured to receive instructionsfrom the memory circuit 804.

FIG. 8 illustrates a combinational logic circuit 810 configured tocontrol aspects of the surgical instrument 10 (FIGS. 1-4) according toone aspect of this disclosure. The combinational logic circuit 810 canbe configured to implement various processes described herein. Thecircuit 810 may comprise a finite state machine comprising acombinational logic circuit 812 configured to receive data associatedwith the surgical instrument 10 at an input 814, process the data by thecombinational logic 812, and provide an output 816.

FIG. 9 illustrates a sequential logic circuit 820 configured to controlaspects of the surgical instrument 10 (FIGS. 1-4) according to oneaspect of this disclosure. The sequential logic circuit 820 or thecombinational logic circuit 822 can be configured to implement variousprocesses described herein. The circuit 820 may comprise a finite statemachine. The sequential logic circuit 820 may comprise a combinationallogic circuit 822, at least one memory circuit 824, and a clock 829, forexample. The at least one memory circuit 820 can store a current stateof the finite state machine. In certain instances, the sequential logiccircuit 820 may be synchronous or asynchronous. The combinational logiccircuit 822 is configured to receive data associated with the surgicalinstrument 10 an input 826, process the data by the combinational logiccircuit 822, and provide an output 828. In other aspects, the circuitmay comprise a combination of the processor 802 and the finite statemachine to implement various processes herein. In other aspects, thefinite state machine may comprise a combination of the combinationallogic circuit 810 and the sequential logic circuit 820.

Aspects may be implemented as an article of manufacture. The article ofmanufacture may include a computer readable storage medium arranged tostore logic, instructions, and/or data for performing various operationsof one or more aspects. For example, the article of manufacture maycomprise a magnetic disk, optical disk, flash memory, or firmwarecontaining computer program instructions suitable for execution by ageneral purpose processor or application specific processor.

FIG. 10 is a diagram of an absolute positioning system 1100 of thesurgical instrument 10 (FIGS. 1-4) where the absolute positioning system1100 comprises a controlled motor drive circuit arrangement comprising asensor arrangement 1102 according to one aspect of this disclosure. Thesensor arrangement 1102 for an absolute positioning system 1100 providesa unique position signal corresponding to the location of a displacementmember 1111. Turning briefly to FIGS. 2-4, in one aspect thedisplacement member 1111 represents the longitudinally movable drivemember 120 (FIG. 2) comprising a rack of drive teeth 122 for meshingengagement with a corresponding drive gear 86 of the gear reducerassembly 84. In other aspects, the displacement member 1111 representsthe firing member 220 (FIG. 3), which could be adapted and configured toinclude a rack of drive teeth. In yet another aspect, the displacementmember 1111 represents the firing bar 172 (FIG. 4) or the I-beam 178(FIG. 4), each of which can be adapted and configured to include a rackof drive teeth. Accordingly, as used herein, the term displacementmember is used generically to refer to any movable member of thesurgical instrument 10 such as the drive member 120, the firing member220, the firing bar 172, the I-beam 178, or any element that can bedisplaced. In one aspect, the longitudinally movable drive member 120 iscoupled to the firing member 220, the firing bar 172, and the I-beam178. Accordingly, the absolute positioning system 1100 can, in effect,track the linear displacement of the I-beam 178 by tracking the lineardisplacement of the longitudinally movable drive member 120. In variousother aspects, the displacement member 1111 may be coupled to any sensorsuitable for measuring linear displacement. Thus, the longitudinallymovable drive member 120, the firing member 220, the firing bar 172, orthe I-beam 178, or combinations, may be coupled to any suitable lineardisplacement sensor. Linear displacement sensors may include contact ornon-contact displacement sensors. Linear displacement sensors maycomprise linear variable differential transformers (LVDT), differentialvariable reluctance transducers (DVRT), a slide potentiometer, amagnetic sensing system comprising a movable magnet and a series oflinearly arranged Hall effect sensors, a magnetic sensing systemcomprising a fixed magnet and a series of movable linearly arranged Halleffect sensors, an optical sensing system comprising a movable lightsource and a series of linearly arranged photo diodes or photodetectors, or an optical sensing system comprising a fixed light sourceand a series of movable linearly arranged photo diodes or photodetectors, or any combination thereof.

An electric motor 1120 can include a rotatable shaft 1116 that operablyinterfaces with a gear assembly 1114 that is mounted in meshingengagement with a set, or rack, of drive teeth on the displacementmember 1111. A sensor element 1126 may be operably coupled to a gearassembly 1114 such that a single revolution of the sensor element 1126corresponds to some linear longitudinal translation of the displacementmember 1111. An arrangement of gearing and sensors can be connected tothe linear actuator via a rack and pinion arrangement or a rotaryactuator via a spur gear or other connection. A power source 1129supplies power to the absolute positioning system 1100 and an outputindicator 1128 may display the output of the absolute positioning system1100. In FIG. 2, the displacement member 1111 represents thelongitudinally movable drive member 120 comprising a rack of drive teeth122 formed thereon for meshing engagement with a corresponding drivegear 86 of the gear reducer assembly 84. The displacement member 1111represents the longitudinally movable firing member 220, firing bar 172,I-beam 178, or combinations thereof.

A single revolution of the sensor element 1126 associated with theposition sensor 1112 is equivalent to a longitudinal linear displacementd1 of the of the displacement member 1111, where d1 is the longitudinallinear distance that the displacement member 1111 moves from point “a”to point “b” after a single revolution of the sensor element 1126coupled to the displacement member 1111. The sensor arrangement 1102 maybe connected via a gear reduction that results in the position sensor1112 completing one or more revolutions for the full stroke of thedisplacement member 1111. The position sensor 1112 may complete multiplerevolutions for the full stroke of the displacement member 1111.

A series of switches 1122 a-1122 n, where n is an integer greater thanone, may be employed alone or in combination with gear reduction toprovide a unique position signal for more than one revolution of theposition sensor 1112. The state of the switches 1122 a-1122 n are fedback to a controller 1104 that applies logic to determine a uniqueposition signal corresponding to the longitudinal linear displacementd1+d2+ . . . dn of the displacement member 1111. The output 1124 of theposition sensor 1112 is provided to the controller 1104. The positionsensor 1112 of the sensor arrangement 1102 may comprise a magneticsensor, an analog rotary sensor like a potentiometer, an array of analogHall-effect elements, which output a unique combination of positionsignals or values.

The absolute positioning system 1100 provides an absolute position ofthe displacement member 1111 upon power up of the instrument withoutretracting or advancing the displacement member 1111 to a reset (zero orhome) position as may be required with conventional rotary encoders thatmerely count the number of steps forwards or backwards that the motor1120 has taken to infer the position of a device actuator, drive bar,knife, and the like.

The controller 1104 may be programmed to perform various functions suchas precise control over the speed and position of the knife andarticulation systems. In one aspect, the controller 1104 includes aprocessor 1108 and a memory 1106. The electric motor 1120 may be abrushed DC motor with a gearbox and mechanical links to an articulationor knife system. In one aspect, a motor driver 1110 may be an A3941available from Allegro Microsystems, Inc. Other motor drivers may bereadily substituted for use in the absolute positioning system 1100. Amore detailed description of the absolute positioning system 1100 isdescribed in U.S. patent application Ser. No. 15/130,590, entitledSYSTEMS AND METHODS FOR CONTROLLING A SURGICAL STAPLING AND CUTTINGINSTRUMENT, the entire disclosure of which is hereby incorporated hereinby reference.

The controller 1104 may be programmed to provide precise control overthe speed and position of the displacement member 1111 and articulationsystems. The controller 1104 may be configured to compute a response inthe software of the controller 1104. The computed response is comparedto a measured response of the actual system to obtain an “observed”response, which is used for actual feedback decisions. The observedresponse is a favorable, tuned, value that balances the smooth,continuous nature of the simulated response with the measured response,which can detect outside influences on the system.

The absolute positioning system 1100 may comprise and/or be programmedto implement a feedback controller, such as a PID, state feedback, andadaptive controller. A power source 1129 converts the signal from thefeedback controller into a physical input to the system, in this casevoltage. Other examples include pulse width modulation (PWM) of thevoltage, current, and force. Other sensor(s) 1118 may be provided tomeasure physical parameters of the physical system in addition toposition measured by the position sensor 1112. In some aspects, theother sensor(s) 1118 can include sensor arrangements such as thosedescribed in U.S. Pat. No. 9,345,481, entitled STAPLE CARTRIDGE TISSUETHICKNESS SENSOR SYSTEM, which is hereby incorporated herein byreference in its entirety; U.S. Patent Application Publication No.2014/0263552, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM,which is hereby incorporated herein by reference in its entirety; andU.S. patent application Ser. No. 15/628,175, entitled TECHNIQUES FORADAPTIVE CONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTINGINSTRUMENT, which is hereby incorporated herein by reference in itsentirety. In a digital signal processing system, absolute positioningsystem 1100 is coupled to a digital data acquisition system where theoutput of the absolute positioning system 1100 will have finiteresolution and sampling frequency. The absolute positioning system 1100may comprise a compare and combine circuit to combine a computedresponse with a measured response using algorithms such as weightedaverage and theoretical control loop that drives the computed responsetowards the measured response. The computed response of the physicalsystem takes into account properties like mass, inertial, viscousfriction, inductance resistance, etc., to predict what the states andoutputs of the physical system will be by knowing the input. Thecontroller 1104 may be a control circuit 700 (FIGS. 5A-5B).

The motor driver 1110 may be an A3941 available from AllegroMicrosystems, Inc. The A3941 driver 1110 is a full-bridge controller foruse with external N-channel power metal oxide semiconductor field effecttransistors (MOSFETs) specifically designed for inductive loads, such asbrush DC motors. The driver 1110 comprises a unique charge pumpregulator provides full (>10 V) gate drive for battery voltages down to7 V and allows the A3941 to operate with a reduced gate drive, down to5.5 V. A bootstrap capacitor may be employed to provide theabove-battery supply voltage required for N-channel MOSFETs. An internalcharge pump for the high-side drive allows DC (100% duty cycle)operation. The full bridge can be driven in fast or slow decay modesusing diode or synchronous rectification. In the slow decay mode,current recirculation can be through the high-side or the lowside FETs.The power FETs are protected from shoot-through by resistor adjustabledead time. Integrated diagnostics provide indication of undervoltage,overtemperature, and power bridge faults, and can be configured toprotect the power MOSFETs under most short circuit conditions. Othermotor drivers may be readily substituted for use in the absolutepositioning system 1100.

Having described a general architecture for implementing aspects of anabsolute positioning system 1100 for a sensor arrangement 1102, thedisclosure now turns to FIGS. 11 and 12 fora description of one aspectof a sensor arrangement 1102 for the absolute positioning system 1100.FIG. 11 is an exploded perspective view of the sensor arrangement 1102for the absolute positioning system 1100 showing a circuit 1205 and therelative alignment of the elements of the sensor arrangement 1102,according to one aspect. The sensor arrangement 1102 for an absolutepositioning system 1100 comprises a position sensor 1200, a magnet 1202sensor element, a magnet holder 1204 that turns once every full strokeof the displacement member 1111, and a gear assembly 1206 to provide agear reduction. With reference briefly to FIG. 2, the displacementmember 1111 may represent the longitudinally movable drive member 120comprising a rack of drive teeth 122 for meshing engagement with acorresponding drive gear 86 of the gear reducer assembly 84. Returningto FIG. 11, a structural element such as bracket 1216 is provided tosupport the gear assembly 1206, the magnet holder 1204, and the magnet1202. The position sensor 1200 comprises magnetic sensing elements suchas Hall elements and is placed in proximity to the magnet 1202. As themagnet 1202 rotates, the magnetic sensing elements of the positionsensor 1200 determine the absolute angular position of the magnet 1202over one revolution.

The sensor arrangement 1102 may comprise any number of magnetic sensingelements, such as, for example, magnetic sensors classified according towhether they measure the total magnetic field or the vector componentsof the magnetic field. The techniques used to produce both types ofmagnetic sensors encompass many aspects of physics and electronics. Thetechnologies used for magnetic field sensing include search coil,fluxgate, optically pumped, nuclear precession, SQUID, Hall-effect,anisotropic magnetoresistance, giant magnetoresistance, magnetic tunneljunctions, giant magnetoimpedance, magnetostrictive/piezoelectriccomposites, magnetodiode, magnetotransistor, fiber optic, magnetooptic,and microelectromechanical systems-based magnetic sensors, among others.

A gear assembly comprises a first gear 1208 and a second gear 1210 inmeshing engagement to provide a 3:1 gear ratio connection. A third gear1212 rotates about a shaft 1214. The third gear 1212 is in meshingengagement with the displacement member 1111 (or 120 as shown in FIG. 2)and rotates in a first direction as the displacement member 1111advances in a distal direction D and rotates in a second direction asthe displacement member 1111 retracts in a proximal direction P. Thesecond gear 1210 also rotates about the shaft 1214 and, therefore,rotation of the second gear 1210 about the shaft 1214 corresponds to thelongitudinal translation of the displacement member 1111. Thus, one fullstroke of the displacement member 1111 in either the distal or proximaldirections D, P corresponds to three rotations of the second gear 1210and a single rotation of the first gear 1208. Since the magnet holder1204 is coupled to the first gear 1208, the magnet holder 1204 makes onefull rotation with each full stroke of the displacement member 1111.

The position sensor 1200 is supported by a position sensor holder 1218defining an aperture 1220 suitable to contain the position sensor 1200in precise alignment with a magnet 1202 rotating below within the magnetholder 1204. The fixture is coupled to the bracket 1216 and to thecircuit 1205 and remains stationary while the magnet 1202 rotates withthe magnet holder 1204. A hub 1222 is provided to mate with the firstgear 1208 and the magnet holder 1204. The second gear 1210 and thirdgear 1212 coupled to shaft 1214 also are shown.

FIG. 12 is a diagram of a position sensor 1200 for an absolutepositioning system 1100 comprising a magnetic rotary absolutepositioning system according to one aspect of this disclosure. Theposition sensor 1200 may be implemented as an AS5055EQFT single-chipmagnetic rotary position sensor available from Austria Microsystems, AG.The position sensor 1200 is interfaced with the controller 1104 toprovide an absolute positioning system 1100. The position sensor 1200 isa low-voltage and low-power component and includes four Hall-effectelements 1228A, 1228B, 1228C, 1228D in an area 1230 of the positionsensor 1200 that is located above the magnet 1202 (FIGS. 15 and 16). Ahigh resolution ADC 1232 and a smart power management controller 1238are also provided on the chip. A CORDIC processor 1236 (for CoordinateRotation Digital Computer), also known as the digit-by-digit method andVolder's algorithm, is provided to implement a simple and efficientalgorithm to calculate hyperbolic and trigonometric functions thatrequire only addition, subtraction, bitshift, and table lookupoperations. The angle position, alarm bits, and magnetic fieldinformation are transmitted over a standard serial communicationinterface such as an SPI interface 1234 to the controller 1104. Theposition sensor 1200 provides 12 or 14 bits of resolution. The positionsensor 1200 may be an AS5055 chip provided in a small QFN 16-pin4×4×0.85 mm package.

The Hall-effect elements 1228A, 1228B, 1228C, 1228D are located directlyabove the rotating magnet 1202 (FIG. 11). The Hall-effect is awell-known effect and for expediency will not be described in detailherein, however, generally, the Hall-effect produces a voltagedifference (the Hall voltage) across an electrical conductor transverseto an electric current in the conductor and a magnetic fieldperpendicular to the current. A Hall coefficient is defined as the ratioof the induced electric field to the product of the current density andthe applied magnetic field. It is a characteristic of the material fromwhich the conductor is made, since its value depends on the type,number, and properties of the charge carriers that constitute thecurrent. In the AS5055 position sensor 1200, the Hall-effect elements1228A, 1228B, 1228C, 1228D are capable producing a voltage signal thatis indicative of the absolute position of the magnet 1202 in terms ofthe angle over a single revolution of the magnet 1202. This value of theangle, which is unique position signal, is calculated by the CORDICprocessor 1236 is stored onboard the AS5055 position sensor 1200 in aregister or memory. The value of the angle that is indicative of theposition of the magnet 1202 over one revolution is provided to thecontroller 1104 in a variety of techniques, e.g., upon power up or uponrequest by the controller 1104.

The AS5055 position sensor 1200 requires only a few external componentsto operate when connected to the controller 1104. Six wires are neededfor a simple application using a single power supply: two wires forpower and four wires 1240 for the SPI interface 1234 with the controller1104. A seventh connection can be added in order to send an interrupt tothe controller 1104 to inform that a new valid angle can be read. Uponpower-up, the AS5055 position sensor 1200 performs a full power-upsequence including one angle measurement. The completion of this cycleis indicated as an INT output 1242, and the angle value is stored in aninternal register. Once this output is set, the AS5055 position sensor1200 suspends to sleep mode. The controller 1104 can respond to the INTrequest at the INT output 1242 by reading the angle value from theAS5055 position sensor 1200 over the SPI interface 1234. Once the anglevalue is read by the controller 1104, the INT output 1242 is clearedagain. Sending a “read angle” command by the SPI interface 1234 by thecontroller 1104 to the position sensor 1200 also automatically powers upthe chip and starts another angle measurement. As soon as the controller1104 has completed reading of the angle value, the INT output 1242 iscleared and a new result is stored in the angle register. The completionof the angle measurement is again indicated by setting the INT output1242 and a corresponding flag in the status register.

Due to the measurement principle of the AS5055 position sensor 1200,only a single angle measurement is performed in very short time (˜600μs) after each power-up sequence. As soon as the measurement of oneangle is completed, the AS5055 position sensor 1200 suspends topower-down state. An on-chip filtering of the angle value by digitalaveraging is not implemented, as this would require more than one anglemeasurement and, consequently, a longer power-up time that is notdesired in low-power applications. The angle jitter can be reduced byaveraging of several angle samples in the controller 1104. For example,an averaging of four samples reduces the jitter by 6 dB (50%).

FIG. 13 is a section view of an end effector 2502 of the surgicalinstrument 10 (FIGS. 1-4) showing an I-beam 2514 firing stroke relativeto tissue 2526 grasped within the end effector 2502 according to oneaspect of this disclosure. The end effector 2502 is configured tooperate with the surgical instrument 10 shown in FIGS. 1-4. The endeffector 2502 comprises an anvil 2516 and an elongated channel 2503 witha staple cartridge 2518 positioned in the elongated channel 2503. Afiring bar 2520 is translatable distally and proximally along alongitudinal axis 2515 of the end effector 2502. When the end effector2502 is not articulated, the end effector 2502 is in line with the shaftof the instrument. An I-beam 2514 comprising a cutting edge 2509 isillustrated at a distal portion of the firing bar 2520. A wedge sled2513 is positioned in the staple cartridge 2518. As the I-beam 2514translates distally, the cutting edge 2509 contacts and may cut tissue2526 positioned between the anvil 2516 and the staple cartridge 2518.Also, the I-beam 2514 contacts the wedge sled 2513 and pushes itdistally, causing the wedge sled 2513 to contact staple drivers 2511.The staple drivers 2511 may be driven up into staples 2505, causing thestaples 2505 to advance through tissue and into pockets 2507 defined inthe anvil 2516, which shape the staples 2505.

An example I-beam 2514 firing stroke is illustrated by a chart 2529aligned with the end effector 2502. Example tissue 2526 is also shownaligned with the end effector 2502. The firing member stroke maycomprise a stroke begin position 2527 and a stroke end position 2528.During an I-beam 2514 firing stroke, the I-beam 2514 may be advanceddistally from the stroke begin position 2527 to the stroke end position2528. The I-beam 2514 is shown at one example location of a stroke beginposition 2527. The I-beam 2514 firing member stroke chart 2529illustrates five firing member stroke regions 2517, 2519, 2521, 2523,2525. In a first firing stroke region 2517, the I-beam 2514 may begin toadvance distally. In the first firing stroke region 2517, the I-beam2514 may contact the wedge sled 2513 and begin to move it distally.While in the first region, however, the cutting edge 2509 may notcontact tissue and the wedge sled 2513 may not contact a staple driver2511. After static friction is overcome, the force to drive the I-beam2514 in the first region 2517 may be substantially constant.

In the second firing member stroke region 2519, the cutting edge 2509may begin to contact and cut tissue 2526. Also, the wedge sled 2513 maybegin to contact staple drivers 2511 to drive staples 2505. Force todrive the I-beam 2514 may begin to ramp up. As shown, tissue encounteredinitially may be compressed and/or thinner because of the way that theanvil 2516 pivots relative to the staple cartridge 2518. In the thirdfiring member stroke region 2521, the cutting edge 2509 may continuouslycontact and cut tissue 2526 and the wedge sled 2513 may repeatedlycontact staple drivers 2511. Force to drive the I-beam 2514 may plateauin the third region 2521. By the fourth firing stroke region 2523, forceto drive the I-beam 2514 may begin to decline. For example, tissue inthe portion of the end effector 2502 corresponding to the fourth firingregion 2523 may be less compressed than tissue closer to the pivot pointof the anvil 2516, requiring less force to cut. Also, the cutting edge2509 and wedge sled 2513 may reach the end of the tissue 2526 while inthe fourth region 2523. When the I-beam 2514 reaches the fifth region2525, the tissue 2526 may be completely severed. The wedge sled 2513 maycontact one or more staple drivers 2511 at or near the end of thetissue. Force to advance the I-beam 2514 through the fifth region 2525may be reduced and, in some examples, may be similar to the force todrive the I-beam 2514 in the first region 2517. At the conclusion of thefiring member stroke, the I-beam 2514 may reach the stroke end position2528. The positioning of firing member stroke regions 2517, 2519, 2521,2523, 2525 in FIG. 18 is just one example. In some examples, differentregions may begin at different positions along the end effectorlongitudinal axis 2515, for example, based on the positioning of tissuebetween the anvil 2516 and the staple cartridge 2518.

As discussed above and with reference now to FIGS. 10-13, the electricmotor 1122 positioned within the handle assembly of the surgicalinstrument 10 (FIGS. 1-4) can be utilized to advance and/or retract thefiring system of the shaft assembly, including the I-beam 2514, relativeto the end effector 2502 of the shaft assembly in order to staple and/orincise tissue captured within the end effector 2502. The I-beam 2514 maybe advanced or retracted at a desired speed, or within a range ofdesired speeds. The controller 1104 may be configured to control thespeed of the I-beam 2514. The controller 1104 may be configured topredict the speed of the I-beam 2514 based on various parameters of thepower supplied to the electric motor 1122, such as voltage and/orcurrent, for example, and/or other operating parameters of the electricmotor 1122 or external influences. The controller 1104 may be configuredto predict the current speed of the I-beam 2514 based on the previousvalues of the current and/or voltage supplied to the electric motor1122, and/or previous states of the system like velocity, acceleration,and/or position. The controller 1104 may be configured to sense thespeed of the I-beam 2514 utilizing the absolute positioning sensorsystem described herein. The controller can be configured to compare thepredicted speed of the I-beam 2514 and the sensed speed of the I-beam2514 to determine whether the power to the electric motor 1122 should beincreased in order to increase the speed of the I-beam 2514 and/ordecreased in order to decrease the speed of the I-beam 2514. Furtherregarding surgical instruments 10 driven by an electric motor 1122 maybe found in U.S. Pat. No. 8,210,411, entitled MOTOR-DRIVEN SURGICALCUTTING INSTRUMENT, which is hereby incorporated herein by reference inits entirety. Further detail regarding surgical instruments 10 includingsensor arrangements may be found in U.S. Pat. No. 7,845,537, entitledSURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES, which is herebyincorporated herein by reference in its entirety.

Force acting on the I-beam 2514 may be determined using varioustechniques. The I-beam 2514 force may be determined by measuring themotor 2504 current, where the motor 2504 current is based on the loadexperienced by the I-beam 2514 as it advances distally. The I-beam 2514force may be determined by positioning a strain gauge on the drivemember 120 (FIG. 2), the firing member 220 (FIG. 2), I-beam 2514 (I-beam178, FIG. 20), the firing bar 172 (FIG. 2), and/or on a proximal end ofthe cutting edge 2509. The I-beam 2514 force may be determined bymonitoring the actual position of the I-beam 2514 moving at an expectedvelocity based on the current set velocity of the motor 2504 after apredetermined elapsed period T₁ and comparing the actual position of theI-beam 2514 relative to the expected position of the I-beam 2514 basedon the current set velocity of the motor 2504 at the end of the periodT₁. Thus, if the actual position of the I-beam 2514 is less than theexpected position of the I-beam 2514, the force on the I-beam 2514 isgreater than a nominal force. Conversely, if the actual position of theI-beam 2514 is greater than the expected position of the I-beam 2514,the force on the I-beam 2514 is less than the nominal force. Thedifference between the actual and expected positions of the I-beam 2514is proportional to the deviation of the force on the I-beam 2514 fromthe nominal force. Such techniques are described in U.S. patentapplication Ser. No. 15/628,075, entitled SYSTEMS AND METHODS FORCONTROLLING MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTINGINSTRUMENT, which is hereby incorporated herein by reference in itsentirety.

FIG. 14 illustrates a block diagram of a surgical instrument 2500programmed to control distal translation of a displacement memberaccording to one aspect of this disclosure. In one aspect, the surgicalinstrument 2500 is programmed to control distal translation of adisplacement member 1111 such as the I-beam 2514. The surgicalinstrument 2500 comprises an end effector 2502 that may comprise ananvil 2516, an I-beam 2514 (including a sharp cutting edge 2509), and aremovable staple cartridge 2518. The end effector 2502, anvil 2516,I-beam 2514, and staple cartridge 2518 may be configured as describedherein, for example, with respect to FIGS. 1-13.

The position, movement, displacement, and/or translation of a linerdisplacement member 1111, such as the I-beam 2514, can be measured bythe absolute positioning system 1100, sensor arrangement 1102, andposition sensor 1200 as shown in FIGS. 10-12 and represented as positionsensor 2534 in FIG. 14. Because the I-beam 2514 is coupled to thelongitudinally movable drive member 120, the position of the I-beam 2514can be determined by measuring the position of the longitudinallymovable drive member 120 employing the position sensor 2534.Accordingly, in the following description, the position, displacement,and/or translation of the I-beam 2514 can be achieved by the positionsensor 2534 as described herein. A control circuit 2510, such as thecontrol circuit 700 described in FIGS. 5A and 5B, may be programmed tocontrol the translation of the displacement member 1111, such as theI-beam 2514, as described in connection with FIGS. 10-12. The controlcircuit 2510, in some examples, may comprise one or moremicrocontrollers, microprocessors, or other suitable processors forexecuting instructions that cause the processor or processors to controlthe displacement member, e.g., the I-beam 2514, in the manner described.In one aspect, a timer/counter circuit 2531 provides an output signal,such as elapsed time or a digital count, to the control circuit 2510 tocorrelate the position of the I-beam 2514 as determined by the positionsensor 2534 with the output of the timer/counter circuit 2531 such thatthe control circuit 2510 can determine the position of the I-beam 2514at a specific time (t) relative to a starting position. Thetimer/counter circuit 2531 may be configured to measure elapsed time,count external evens, or time external events.

The control circuit 2510 may generate a motor set point signal 2522. Themotor set point signal 2522 may be provided to a motor controller 2508.The motor controller 2508 may comprise one or more circuits configuredto provide a motor drive signal 2524 to the motor 2504 to drive themotor 2504 as described herein. In some examples, the motor 2504 may bea brushed DC electric motor, such as the motor 82, 714, 1120 shown inFIGS. 1, 5B, 10. For example, the velocity of the motor 2504 may beproportional to the motor drive signal 2524. In some examples, the motor2504 may be a brushless direct current (DC) electric motor and the motordrive signal 2524 may comprise a pulse-width-modulated (PWM) signalprovided to one or more stator windings of the motor 2504. Also, in someexamples, the motor controller 2508 may be omitted and the controlcircuit 2510 may generate the motor drive signal 2524 directly.

The motor 2504 may receive power from an energy source 2512. The energysource 2512 may be or include a battery, a super capacitor, or any othersuitable energy source 2512. The motor 2504 may be mechanically coupledto the I-beam 2514 via a transmission 2506. The transmission 2506 mayinclude one or more gears or other linkage components to couple themotor 2504 to the I-beam 2514. A position sensor 2534 may sense aposition of the I-beam 2514. The position sensor 2534 may be or includeany type of sensor that is capable of generating position data thatindicates a position of the I-beam 2514. In some examples, the positionsensor 2534 may include an encoder configured to provide a series ofpulses to the control circuit 2510 as the I-beam 2514 translatesdistally and proximally. The control circuit 2510 may track the pulsesto determine the position of the I-beam 2514. Other suitable positionsensor may be used, including, for example, a proximity sensor. Othertypes of position sensors may provide other signals indicating motion ofthe I-beam 2514. Also, in some examples, the position sensor 2534 may beomitted. Where the motor 2504 is a stepper motor, the control circuit2510 may track the position of the I-beam 2514 by aggregating the numberand direction of steps that the motor 2504 has been instructed toexecute. The position sensor 2534 may be located in the end effector2502 or at any other portion of the instrument.

The control circuit 2510 may be in communication with one or moresensors 2538. The sensors 2538 may be positioned on the end effector2502 and adapted to operate with the surgical instrument 2500 to measurethe various derived parameters such as gap distance versus time, tissuecompression versus time, and anvil strain versus time. The sensors 2538may comprise a magnetic sensor, a magnetic field sensor, a strain gauge,a pressure sensor, a force sensor, an inductive sensor such as an eddycurrent sensor, a resistive sensor, a capacitive sensor, an opticalsensor, and/or any other suitable sensor for measuring one or moreparameters of the end effector 2502. The sensors 2538 may include one ormore sensors.

The one or more sensors 2538 may comprise a strain gauge, such as amicro-strain gauge, configured to measure the magnitude of the strain inthe anvil 2516 during a clamped condition. The strain gauge provides anelectrical signal whose amplitude varies with the magnitude of thestrain. The sensors 2538 may comprise a pressure sensor configured todetect a pressure generated by the presence of compressed tissue betweenthe anvil 2516 and the staple cartridge 2518. The sensors 2538 may beconfigured to detect impedance of a tissue section located between theanvil 2516 and the staple cartridge 2518 that is indicative of thethickness and/or fullness of tissue located therebetween.

The sensors 2538 may be is configured to measure forces exerted on theanvil 2516 by the closure drive system 30. For example, one or moresensors 2538 can be at an interaction point between the closure tube 260(FIG. 3) and the anvil 2516 to detect the closure forces applied by theclosure tube 260 to the anvil 2516. The forces exerted on the anvil 2516can be representative of the tissue compression experienced by thetissue section captured between the anvil 2516 and the staple cartridge2518. The one or more sensors 2538 can be positioned at variousinteraction points along the closure drive system 30 (FIG. 2) to detectthe closure forces applied to the anvil 2516 by the closure drive system30. The one or more sensors 2538 may be sampled in real time during aclamping operation by a processor as described in FIGS. 5A-5B. Thecontrol circuit 2510 receives real-time sample measurements to provideanalyze time based information and assess, in real time, closure forcesapplied to the anvil 2516.

A current sensor 2536 can be employed to measure the current drawn bythe motor 2504. The force required to advance the I-beam 2514corresponds to the current drawn by the motor 2504. The force isconverted to a digital signal and provided to the control circuit 2510.

Using the physical properties of the instruments disclosed herein inconnection with FIGS. 1-13, and with reference to FIG. 14, the controlcircuit 2510 can be configured to simulate the response of the actualsystem of the instrument in the software of the controller. Adisplacement member can be actuated to move an I-beam 2514 in the endeffector 2502 at or near a target velocity. The surgical instrument 2500can include a feedback controller, which can be one of any feedbackcontrollers, including, but not limited to a PID, a State Feedback, LQR,and/or an Adaptive controller, for example. The surgical instrument 2500can include a power source to convert the signal from the feedbackcontroller into a physical input such as case voltage, pulse widthmodulated (PWM) voltage, frequency modulated voltage, current, torque,and/or force, for example.

The actual drive system of the surgical instrument 2500 is configured todrive the displacement member, cutting member, or I-beam 2514, by abrushed DC motor with gearbox and mechanical links to an articulationand/or knife system. Another example is the electric motor 2504 thatoperates the displacement member and the articulation driver, forexample, of an interchangeable shaft assembly. An outside influence isan unmeasured, unpredictable influence of things like tissue,surrounding bodies and friction on the physical system. Such outsideinfluence can be referred to as drag which acts in opposition to theelectric motor 2504. The outside influence, such as drag, may cause theoperation of the physical system to deviate from a desired operation ofthe physical system.

Before explaining aspects of the surgical instrument 2500 in detail, itshould be noted that the example aspects are not limited in applicationor use to the details of construction and arrangement of partsillustrated in the accompanying drawings and description. The exampleaspects may be implemented or incorporated in other aspects, variationsand modifications, and may be practiced or carried out in various ways.Further, unless otherwise indicated, the terms and expressions employedherein have been chosen for the purpose of describing the exampleaspects for the convenience of the reader and are not for the purpose oflimitation thereof. Also, it will be appreciated that one or more of thefollowing-described aspects, expressions of aspects and/or examples, canbe combined with any one or more of the other following-describedaspects, expressions of aspects and/or examples.

Various example aspects are directed to a surgical instrument 2500comprising an end effector 2502 with motor-driven surgical stapling andcutting implements. For example, a motor 2504 may drive a displacementmember distally and proximally along a longitudinal axis of the endeffector 2502. The end effector 2502 may comprise a pivotable anvil 2516and, when configured for use, a staple cartridge 2518 positionedopposite the anvil 2516. A clinician may grasp tissue between the anvil2516 and the staple cartridge 2518, as described herein. When ready touse the instrument 2500, the clinician may provide a firing signal, forexample by depressing a trigger of the instrument 2500. In response tothe firing signal, the motor 2504 may drive the displacement memberdistally along the longitudinal axis of the end effector 2502 from aproximal stroke begin position to a stroke end position distal of thestroke begin position. As the displacement member translates distally,an I-beam 2514 with a cutting element positioned at a distal end, maycut the tissue between the staple cartridge 2518 and the anvil 2516.

In various examples, the surgical instrument 2500 may comprise a controlcircuit 2510 programmed to control the distal translation of thedisplacement member, such as the I-beam 2514, for example, based on oneor more tissue conditions. The control circuit 2510 may be programmed tosense tissue conditions, such as thickness, either directly orindirectly, as described herein. The control circuit 2510 may beprogrammed to select a firing control program based on tissueconditions. A firing control program may describe the distal motion ofthe displacement member. Different firing control programs may beselected to better treat different tissue conditions. For example, whenthicker tissue is present, the control circuit 2510 may be programmed totranslate the displacement member at a lower velocity and/or with lowerpower. When thinner tissue is present, the control circuit 2510 may beprogrammed to translate the displacement member at a higher velocityand/or with higher power.

In some examples, the control circuit 2510 may initially operate themotor 2504 in an open loop configuration for a first open loop portionof a stroke of the displacement member. Based on a response of theinstrument 2500 during the open loop portion of the stroke, the controlcircuit 2510 may select a firing control program. The response of theinstrument may include, a translation distance of the displacementmember during the open loop portion, a time elapsed during the open loopportion, energy provided to the motor 2504 during the open loop portion,a sum of pulse widths of a motor drive signal, etc. After the open loopportion, the control circuit 2510 may implement the selected firingcontrol program for a second portion of the displacement member stroke.For example, during the closed loop portion of the stroke, the controlcircuit 2510 may modulate the motor 2504 based on translation datadescribing a position of the displacement member in a closed loop mannerto translate the displacement member at a constant velocity.

FIG. 15 illustrates a diagram 2580 plotting two example displacementmember strokes executed according to one aspect of this disclosure. Thediagram 2580 comprises two axes. A horizontal axis 2584 indicateselapsed time. A vertical axis 2582 indicates the position of the I-beam2514 between a stroke begin position 2586 and a stroke end position2588. On the horizontal axis 2584, the control circuit 2510 may receivethe firing signal and begin providing the initial motor setting at t₀.The open loop portion of the displacement member stroke is an initialtime period that may elapse between t₀ and t₁.

A first example 2592 shows a response of the surgical instrument 2500when thick tissue is positioned between the anvil 2516 and the staplecartridge 2518. During the open loop portion of the displacement memberstroke, e.g., the initial time period between t₀ and t₁, the I-beam 2514may traverse from the stroke begin position 2586 to position 2594. Thecontrol circuit 2510 may determine that position 2594 corresponds to afiring control program that advances the I-beam 2514 at a selectedconstant velocity (V_(slow)), indicated by the slope of the example 2592after t₁ (e.g., in the closed loop portion). The control circuit 2510may drive I-beam 2514 to the velocity V_(slow) by monitoring theposition of I-beam 2514 and modulating the motor set point signal 2522and/or motor drive signal 2524 to maintain V_(slow).

A second example 2590 shows a response of the surgical instrument 2500when thin tissue is positioned between the anvil 2516 and the staplecartridge 2518. During the initial time period (e.g., the open loopperiod) between t₀ and t₁, the I-beam 2514 may traverse from the strokebegin position 2586 to position 2596. The control circuit may determinethat position 2596 corresponds to a firing control program that advancesthe displacement member at a selected constant velocity (V_(fast)).Because the tissue in example 2590 is thinner than the tissue in example2592, it may provide less resistance to the motion of the I-beam 2514.As a result, the I-beam 2514 may traverse a larger portion of the strokeduring the initial time period. Also, in some examples, thinner tissue(e.g., a larger portion of the displacement member stroke traversedduring the initial time period) may correspond to higher displacementmember velocities after the initial time period.

FIGS. 16-21 illustrate an end effector 2300 of a surgical instrument2010 showing how the end effector 2300 may be articulated relative tothe elongate shaft assembly 2200 about an articulation joint 2270according to one aspect of this disclosure. FIG. 16 is a partialperspective view of a portion of the end effector 2300 showing anelongate shaft assembly 2200 in an unarticulated orientation withportions thereof omitted for clarity. FIG. 17 is a perspective view ofthe end effector 2300 of FIG. 16 showing the elongate shaft assembly2200 in an unarticulated orientation. FIG. 18 is an exploded assemblyperspective view of the end effector 2300 of FIG. 16 showing theelongate shaft assembly 2200. FIG. 19 is a top view of the end effector2300 of FIG. 16 showing the elongate shaft assembly 2200 in anunarticulated orientation. FIG. 20 is a top view of the end effector2300 of FIG. 16 showing the elongate shaft assembly 2200 in a firstarticulated orientation. FIG. 21 is a top view of the end effector 2300of FIG. 16 showing the elongate shaft assembly 2200 in a secondarticulated orientation.

With reference now to FIGS. 16-21, the end effector 2300 is adapted tocut and staple tissue and includes a first jaw in the form of anelongated channel 2302 that is configured to operably support a surgicalstaple cartridge 2304 therein. The end effector 2300 further includes asecond jaw in the form of an anvil 2310 that is supported on theelongated channel 2302 for movement relative thereto. The elongate shaftassembly 2200 includes an articulation system 2800 that employs anarticulation lock 2810. The articulation lock 2810 can be configured andoperated to selectively lock the surgical end effector 2300 in variousarticulated positions. Such arrangement enables the surgical endeffector 2300 to be rotated, or articulated, relative to the shaftclosure tube 260 when the articulation lock 2810 is in its unlockedstate. Referring specifically to FIG. 18, the elongate shaft assembly2200 includes a spine 210 that is configured to (1) slidably support afiring member 220 therein and, (2) slidably support the closure tube 260(FIG. 16), which extends around the spine 210. The shaft closure tube260 is attached to an end effector closure sleeve 272 that is pivotallyattached to the closure tube 260 by a double pivot closure sleeveassembly 271.

The spine 210 also slidably supports a proximal articulation driver 230.The proximal articulation driver 230 has a distal end 231 that isconfigured to operably engage the articulation lock 2810. Thearticulation lock 2810 further comprises a shaft frame 2812 that isattached to the spine 210 in the various manners disclosed herein. Theshaft frame 2812 is configured to movably support a proximal portion2821 of a distal articulation driver 2820 therein. The distalarticulation driver 2820 is movably supported within the elongate shaftassembly 2200 for selective longitudinal travel in a distal direction DDand a proximal direction PD along an articulation actuation axis AAAthat is laterally offset and parallel to the shaft axis SA-SA inresponse to articulation control motions applied thereto.

In FIGS. 17 and 18, the shaft frame 2812 includes a distal end portion2814 that has a pivot pin 2818 formed thereon. The pivot pin 2818 isadapted to be pivotally received within a pivot hole 2397 formed inpivot base portion 2395 of an end effector mounting assembly 2390. Theend effector mounting assembly 2390 is attached to the proximal end 2303of the elongated channel 2302 by a spring pin 2393 or equivalent. Thepivot pin 2818 defines an articulation axis B-B transverse to the shaftaxis SA-SA to facilitate pivotal travel (i.e., articulation) of the endeffector 2300 about the articulation axis B-B relative to the shaftframe 2812.

As shown in FIG. 18, a link pin 2825 is formed on a distal end 2823 ofthe distal articulation driver 2820 and is configured to be receivedwithin a hole 2904 in a proximal end 2902 of a cross link 2900. Thecross link 2900 extends transversely across the shaft axis SA-SA andincludes a distal end portion 2906. A distal link hole 2908 is providedthrough the distal end portion 2906 of the cross link 2900 and isconfigured to pivotally receive therein a base pin 2398 extending fromthe bottom of the pivot base portion 2395 of the end effector mountingassembly 2390. The base pin 2398 defines a link axis LA that is parallelto the articulation axis B-B. FIGS. 17 and 20 illustrate the surgicalend effector 2300 in an unarticulated position. The end effector axis EAis defined by the elongated channel 2302 is aligned with the shaft axisSA-SA. The term “aligned with” may mean “coaxially aligned” with theshaft axis SA-SA or parallel with the shaft axis SA-SA. Movement of thedistal articulation driver 2820 in the proximal direction PD will causethe cross link 2900 to draw the surgical end effector 2300 in aclockwise CW direction about the articulation axis B-B as shown in FIG.19. Movement of the distal articulation driver 2820 in the distaldirection DD will cause the cross link 2900 to move the surgical endeffector 2300 in the counterclockwise CCW direction about thearticulation axis B-B as shown in FIG. 21. As shown in FIG. 21, thecross link 2900 has a curved shape that permits the cross link 2900 tocurve around the pivot pin 2818 when the surgical end effector 2300 isarticulated in that direction. When the surgical end effector 2300 is ina fully articulated position on either side of the shaft axis SA-SA, thearticulation angle 2700 between the end effector axis EA and the shaftaxis SA-SA is approximately sixty-five degrees (65°). Thus, the range ofarticulation on either said of the shaft axis is from one degree (1°) tosixty-five degrees (65°).

FIG. 19 shows the articulation joint 2270 in a straight position, i.e.,at a zero angle θ₀ relative to the longitudinal direction depicted asshaft axis SA, according to one aspect. FIG. 20 shows the articulationjoint 2270 of FIG. 19 articulated in one direction at a first angle θ₁defined between the shaft axis SA and the end effector axis EA,according to one aspect. FIG. 21 illustrates the articulation joint 2270of FIG. 19 articulated in another direction at a second angle θ₂ definedbetween the shaft axis SA and the end effector axis EA.

The surgical end effector 2300 in FIGS. 16-21 comprises a surgicalcutting and stapling device that employs a firing member 220 of thevarious types and configurations described herein. However, the surgicalend effector 2300 may comprise other forms of surgical end effectorsthat do not cut and/or staple tissue. A middle support member 2950 ispivotally and slidably supported relative to the spine 210. In FIG. 18,the middle support member 2950 includes a slot 2952 that is adapted toreceive therein a pin 2954 that protrudes from the spine 210. Thisenables the middle support member 2950 to pivot and translate relativeto the pin 2954 when the surgical end effector 2300 is articulated. Apivot pin 2958 protrudes from the underside of the middle support member2950 to be pivotally received within a corresponding pivot hole 2399provided in the base portion 2395 of the end effector mounting assembly2390. The middle support member 2950 further includes a slot 2960 forreceiving a firing member 220 there through. The middle support member2950 serves to provide lateral support to the firing member 220 as itflexes to accommodate articulation of the surgical end effector 2300.

The surgical instrument can additionally be configured to determine theangle at which the end effector 2300 is oriented. In various aspects,the position sensor 1112 of the sensor arrangement 1102 may comprise oneor more magnetic sensors, analog rotary sensors (such aspotentiometers), arrays of analog Hall effect sensors, which output aunique combination of position signals or values, among others, forexample. In one aspect, the articulation joint 2270 of the aspectillustrated in FIGS. 16-21 can additionally comprise an articulationsensor arrangement that is configured to determine the angular position,i.e., articulation angle, of the end effector 2300 and provide a uniqueposition signal corresponding thereto.

The articulation sensor arrangement can be similar to the sensorarrangement 1102 described above and illustrated in FIGS. 10-12. In thisaspect, the articulation sensor arrangement can comprise a positionsensor and a magnet that is operatively coupled to the articulationjoint 2270 such that it rotates in a manner consistent with the rotationof the articulation joint 2270. The magnet can, for example, be coupledto the pivot pin 2818. The position sensor comprises one or moremagnetic sensing elements, such as Hall effect sensors, and is placed inproximity to the magnet, either within or adjacent to the articulationjoint 2270. Accordingly, as the magnet rotates, the magnetic sensingelements of the position sensor determine the magnet's absolute angularposition. As the magnet is coupled to the articulation joint 2270, theangular position of the magnet with respect to the position sensorcorresponds to the angular position of the end effector 2300. Therefore,the articulation sensor arrangement is able to determine the angularposition of the end effector as the end effector articulates.

In another aspect, the surgical instrument is configured to determinethe angle at which the end effector 2300 is positioned in an indirectmanner by monitoring the absolute position of the articulation driver230 (FIG. 3). As the position of the articulation driver 230 correspondsto the angle at which the end effector 2300 is oriented in a knownmanner, the absolute position of the articulation driver 230 can betracked and then translated to the angular position of the end effector2300. In this aspect, the surgical instrument comprises an articulationsensor arrangement that is configured to determine the absolute linearposition of the articulation driver 230 and provide a unique positionsignal corresponding thereto. In some aspects, the articulation sensorarrangement or the controller operably coupled to the articulationsensor arrangement is configured additionally to translate or calculatethe angular position of the end effector 2300 from the unique positionsignal.

The articulation sensor arrangement in this aspect can likewise besimilar to the sensor arrangement 1102 described above and illustratedin FIGS. 10-12. In one aspect similar to the aspect illustrated in FIG.10 with respect to the displacement member 1111, the articulation sensorarrangement comprises a position sensor and a magnet that turns onceevery full stroke of the longitudinally-movable articulation driver 230.The position sensor comprises one or more magnetic sensing elements,such as Hall effect sensors, and is placed in proximity to the magnet.Accordingly, as the magnet rotates, the magnetic sensing elements of theposition sensor determine the absolute angular position of the magnetover one revolution.

In one aspect, a single revolution of a sensor element associated withthe position sensor is equivalent to a longitudinal linear displacementd1 of the of the longitudinally-movable articulation driver 230. Inother words, d1 is the longitudinal linear distance that thelongitudinally-movable articulation driver 230 moves from point “a” topoint “b” after a single revolution of a sensor element coupled to thelongitudinally-movable articulation driver 230. The articulation sensorarrangement may be connected via a gear reduction that results in theposition sensor completing only one revolution for the full stroke ofthe longitudinally-movable articulation driver 230. In other words, d1can be equal to the full stroke of the articulation driver 230. Theposition sensor is configured to then transmit a unique position signalcorresponding to the absolute position of the articulation driver 230 tothe controller 1104, such as in those aspects depicted in FIG. 10 Uponreceiving the unique position signal, the controller 1104 is thenconfigured execute a logic to determine the angular position of the endeffector corresponding to the linear position of the articulation driver230 by, for example, querying a lookup table that returns the value ofthe pre-calculated angular position of the end effector 2300,calculating via an algorithm the angular position of the end effector2300 utilizing the linear position of the articulation driver 230 as theinput, or performing any other such method as is known in the field.

In various aspects, any number of magnetic sensing elements may beemployed on the articulation sensor arrangement, such as, for example,magnetic sensors classified according to whether they measure the totalmagnetic field or the vector components of the magnetic field. Thenumber of magnetic sensing elements utilized corresponds to the desiredresolution to be sensed by the articulation sensor arrangement. In otherwords, the larger number of magnetic sensing elements used, the finerdegree of articulation that can be sensed by the articulation sensorarrangement. The techniques used to produce both types of magneticsensors encompass many aspects of physics and electronics. Thetechnologies used for magnetic field sensing include search coil,fluxgate, optically pumped, nuclear precession, SQUID, Hall-effect,anisotropic magnetoresistance, giant magnetoresistance, magnetic tunneljunctions, giant magnetoimpedance, magnetostrictive/piezoelectriccomposites, magnetodiode, magnetotransistor, fiber optic, magnetooptic,and microelectromechanical systems-based magnetic sensors, among others.

In one aspect, the position sensor of the various aspects of thearticulation sensor arrangement may be implemented in a manner similarto the positioning system illustrated in FIG. 12 for tracking theposition of the displacement member 1111. In one such aspect, thearticulation sensor arrangement may be implemented as an AS5055EQFTsingle-chip magnetic rotary position sensor available from AustriaMicrosystems, AG. The position sensor is interfaced with the controllerto provide an absolute positioning system for determining the absoluteangular position of the end effector 2300, either directly orindirectly. The position sensor is a low voltage and low power componentand includes four Hall-effect elements 1228A, 1228B, 1228C, 1228D in anarea 1230 of the position sensor 1200 that is located above the magnet1202 (FIG. 11). A high resolution ADC 1232 and a smart power managementcontroller 1238 are also provided on the chip. A CORDIC processor 1236(for Coordinate Rotation Digital Computer), also known as thedigit-by-digit method and Volder's algorithm, is provided to implement asimple and efficient algorithm to calculate hyperbolic and trigonometricfunctions that require only addition, subtraction, bitshift, and tablelookup operations. The angle position, alarm bits and magnetic fieldinformation are transmitted over a standard serial communicationinterface such as an SPI interface 1234 to the controller 1104. Theposition sensor 1200 provides 12 or 14 bits of resolution. The positionsensor 1200 may be an AS5055 chip provided in a small QFN 16-pin4×4×0.85 mm package.

With reference to FIGS. 1-4 and 10-12, the position of the articulationjoint 2270 and the position of the I-beam 178 (FIG. 4) can be determinedwith the absolute position feedback signal/value from the absolutepositioning system 1100. In one aspect, the articulation angle can bedetermined based on the drive member 120 of the surgical instrument 10.As described above, the movement of the longitudinally movable drivemember 120 (FIG. 2) can be tracked by the absolute positioning system1100 wherein, when the articulation drive is operably coupled to thefiring member 220 (FIG. 3) by the clutch assembly 400 (FIG. 3), forexample, the absolute positioning system 1100 can, in effect, track themovement of the articulation system via the drive member 120. As aresult of tracking the movement of the articulation system, thecontroller of the surgical instrument can track the articulation angle θof the end effector 2300. In various circumstances, as a result, thearticulation angle θ can be determined as a function of longitudinaldisplacement of the drive member 120. Since the longitudinaldisplacement of the drive member 120 can be precisely determined basedon the absolute position signal/value provided by the absolutepositioning system 1100, the articulation angle θ can be determined as afunction of longitudinal displacement.

In another aspect, the articulation angle θ can be determined bylocating sensors at the articulation joint 2270. The sensors can beconfigured to sense rotation of the articulation joint 2270 using theabsolute positioning system 1100 in a manner adapted to measure absoluterotation of the articulation joint 2270, rather than the longitudinaldisplacement of the drive member 120, as described above. For example,the sensor arrangement 1102 comprises a position sensor 1200, a magnet1202, and a magnet holder 1204 adapted to sense rotation of thearticulation joint 2270. The position sensor 1200 comprises one or morethan one magnetic sensing elements such as Hall elements and is placedin proximity to the magnet 1202. The position sensor 1200 described inFIG. 12 can be adapted to measure the rotation angle of the articulationjoint 2270. Accordingly, as the magnet 1202 rotates, the magneticsensing elements of the position sensor 1200 determine the absoluteangular position of the magnet 1202 located on the articulation joint2270. This information is provided to the controller 1104 to calculatethe articulation angle of the articulation joint 2270. Accordingly, thearticulation angle of the end effector 2300 can be determined by theabsolute positioning system 1100 adapted to measure absolute rotation ofthe articulation joint 2270.

In one aspect, the firing rate or velocity of the I-beam 178 may bevaried as a function of end effector 2300 articulation angle to lowerthe force-to-fire on the firing drive system 80 and, in particular, theforce-to-fire of the I-beam 178, among other components of the firingdrive system 80 discussed herein. To adapt to the variable firing forceof the I-beam 178 as a function of end effector 2300 articulation angle,a variable motor control voltage can be applied to the motor 82 tocontrol the velocity of the motor 82. The velocity of the motor 82 maybe controlled by comparing the I-beam 178 firing force to differentmaximum thresholds based on articulation angle of the end effector 2300.The velocity of the electric motor 82 can be varied by adjusting thevoltage, current, pulse width modulation (PWM), or duty cycle (0-100%)applied to the motor 82, for example.

FIGS. 22 and 23 depict a motor-driven surgical instrument 10 that may beused to perform a variety of different surgical procedures. The surgicalinstrument 10 can comprise an end effector 3602, which can comprise oneor more electrodes. The end effector 3602 can be positioned againsttissue such that electrical current may be introduced into the tissue.The surgical instrument 10 can be configured for monopolar or bipolaroperation. During monopolar operation, current may be introduced intothe tissue by an active (or source) electrode on the end effector 3602and returned through a return electrode. The return electrode may be agrounding pad and separately located on a patient's body. During bipolaroperation, current may be introduced into and returned from the tissueby the active and return electrodes, respectively, of the end effector.

The end effector 3602 can comprise a first jaw 3604 and a second jawmember 3608. At least one of the jaw members 3604, 3608 may have atleast one electrode. At least one of the jaw members 3604, 3608 may bemoveable from a position spaced apart from the opposing jaw forreceiving tissues to a position in which the space between the jawmembers 3604, 3608 is less than that of the first position. Thismovement of the moveable jaw may compress the tissue held between. Heatgenerated by the current flow through the tissue in combination with thecompression achieved by the jaw's movement may form hemostatic sealswithin the tissue and/or between tissues and, thus, may be particularlyuseful for sealing blood vessels, for example. The surgical instrument10 may comprise a knife member 3628 that is extendable through the endeffector 3602. The knife member 3628 may be movable relative to thetissue and the electrodes to transect the tissue.

The surgical instrument 10 may include mechanisms to clamp tissuetogether, such as a stapling device, and/or mechanisms to sever tissue,such as a tissue knife. The electrosurgical instrument 10 may include ashaft for placing the end effector 3602 proximate to tissue undergoingtreatment. The shaft may be straight or curved, bendable ornon-bendable. In an electrosurgical instrument 10 including a straightand bendable shaft, the shaft may have one or more articulation jointsto permit controlled bending of the shaft. Such joints may permit a userof the electrosurgical instrument 10 to place the end effector incontact with tissue at an angle to the shaft when the tissue beingtreated is not readily accessible using an electrosurgical device havinga straight, non-bending shaft.

Electrical energy applied by electrosurgical devices can be transmittedto the instrument by a generator 3400 in communication with the handleassembly 3500. The electrical energy may be in the form of radiofrequency (“RF”) energy. RF energy is a form of electrical energy thatmay be in the frequency range of 200 kilohertz (kHz) to 1 megahertz(MHz). In application, an electrosurgical instrument can transmit lowfrequency RF energy through tissue, which causes ionic agitation, orfriction, in effect resistive heating, thereby increasing thetemperature of the tissue. Because a sharp boundary is created betweenthe affected tissue and the surrounding tissue, surgeons can operatewith a high level of precision and control, without sacrificingun-targeted adjacent tissue. The low operating temperatures of RF energyis useful for removing, shrinking, or sculpting soft tissue whilesimultaneously sealing blood vessels. RF energy works particularly wellon connective tissue, which is primarily comprised of collagen andshrinks when contacted by heat.

The RF energy may be in a frequency range described in EN60601-2-2:2009+A11:2011, Definition 201.3.218—HIGH FREQUENCY. Forexample, the frequency in monopolar RF applications may be typicallyrestricted to less than 5 MHz. However, in bipolar RF applications, thefrequency can be almost anything. Frequencies above 200 kHz can betypically used for monopolar applications in order to avoid the unwantedstimulation of nerves and muscles that would result from the use of lowfrequency current. Lower frequencies may be used for bipolarapplications if the risk analysis shows the possibility of neuromuscularstimulation has been mitigated to an acceptable level. Normally,frequencies above 5 MHz are not used in order to minimize the problemsassociated with high frequency leakage currents. Higher frequencies may,however, be used in the case of bipolar applications. It is generallyrecognized that 10 mA is the lower threshold of thermal effects ontissue.

In the illustrated arrangement, the surgical instrument 10 comprises aninterchangeable surgical tool assembly 3600 that is operably coupled toa handle assembly 3500. In another surgical system aspect, theinterchangeable surgical tool assembly 3600 may also be effectivelyemployed with a tool drive assembly of a robotically controlled orautomated surgical system. For example, the surgical tool assembly 3600disclosed herein may be employed with various robotic systems,instruments, components and methods such as, but not limited to, thosedisclosed in U.S. Pat. No. 9,072,535, entitled SURGICAL STAPLINGINSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which ishereby incorporated herein by reference in its entirety.

In the illustrated aspect, the handle assembly 3500 may comprise ahandle housing 3502 that includes a pistol grip portion that can begripped and manipulated by the clinician. As will be briefly discussedbelow, the handle assembly 3500 operably supports a plurality of drivesystems that are configured to generate and apply various controlmotions to corresponding portions of the interchangeable surgical toolassembly 3600. As shown in FIG. 22, the handle assembly 3500 may furtherinclude a handle frame 3506 that operably supports the plurality ofdrive systems. For example, the handle frame 3506 can operably support a“first” or closure drive system, generally designated as 3510, which maybe employed to apply closing and opening motions to the interchangeablesurgical tool assembly 3600. In at least one form, the closure drivesystem 3510 may include an actuator in the form of a closure trigger3512 that is pivotally supported by the handle frame 3506. Sucharrangement enables the closure trigger 3512 to be manipulated by aclinician such that when the clinician grips the pistol grip portion 504of the handle assembly 3500, the closure trigger 3512 may be easilypivoted from a starting or “unactuated” position to an “actuated”position and more particularly to a fully compressed or fully actuatedposition. In use, to actuate the closure drive system 3510, theclinician depresses the closure trigger 3512 towards the pistol gripportion. As described in further detail in U.S. Patent ApplicationPublication No. 2015/0272575, entitled SURGICAL INSTRUMENT COMPRISING ASENSOR SYSTEM, which is hereby incorporated herein by reference in itsentirety, when the clinician fully depresses the closure trigger 3512 toattain the full closure stroke, the closure drive system 3510 isconfigured to lock the closure trigger 3512 into the fully depressed orfully actuated position. When the clinician desires to unlock theclosure trigger 3512 to permit it to be biased to the unactuatedposition, the clinician simply activates a closure release buttonassembly 3518 which enables the closure trigger to return to unactuatedposition. The closure release button assembly 3518 may also beconfigured to interact with various sensors that communicate with amicrocontroller in the handle assembly 3500 for tracking the position ofthe closure trigger 3512. Further details concerning the configurationand operation of the closure release button assembly 3518 may be foundin U.S. Patent Application Publication No. 2015/0272575.

In at least one form, the handle assembly 3500 and the handle frame 3506may operably support another drive system referred to herein as a firingdrive system 3530 that is configured to apply firing motions tocorresponding portions of the interchangeable surgical tool assemblythat is attached thereto. As was described in detail in U.S. PatentApplication Publication No. 2015/0272575, the firing drive system 3530may employ an electric motor 3505 that is located in the pistol gripportion of the handle assembly 3500. In various forms, the motor 3505may be a DC brushed driving motor having a maximum rotation of,approximately, 25,000 RPM, for example. In other arrangements, the motor3505 may include a brushless motor, a cordless motor, a synchronousmotor, a stepper motor, or any other suitable electric motor. The motor3505 may be powered by a power source 3522 that in one form may comprisea removable power pack. The power pack may support a plurality ofLithium Ion (“LI”) or other suitable batteries therein. A number ofbatteries may be connected in series may be used as the power source3522 for the surgical instrument 10. In addition, the power source 3522may be replaceable and/or rechargeable.

The electric motor 3505 is configured to axially drive a longitudinallymovable drive member 3540 in a distal and proximal directions dependingupon the polarity of the motor. For example, when the motor 3505 isdriven in one rotary direction, the longitudinally movable drive memberwill be axially driven in a distal direction “DD.” When the motor 3505is driven in the opposite rotary direction, the longitudinally movabledrive member 3540 will be axially driven in a proximal direction “PD.”The handle assembly 3500 can include a switch 3513 which can beconfigured to reverse the polarity applied to the electric motor 3505 bythe power source 3522 or otherwise control the motor 3505. The handleassembly 3500 can also include a sensor or sensors (not shown) that isconfigured to detect the position of the drive member and/or thedirection in which the drive member is being moved. Actuation of themotor 3505 can be controlled by a firing trigger (not shown) that isadjacent to the closure trigger 3512 and pivotally supported on thehandle assembly 3500. The firing trigger may be pivoted between anunactuated position and an actuated position. The firing trigger may bebiased into the unactuated position by a spring or other biasingarrangement such that when the clinician releases the firing trigger, itmay be pivoted or otherwise returned to the unactuated position by thespring or biasing arrangement. In at least one form, the firing triggercan be positioned “outboard” of the closure trigger 3512. As discussedin U.S. Patent Application Publication No. 2015/0272575, the handleassembly 3500 may be equipped with a firing trigger safety button (notshown) to prevent inadvertent actuation of the firing trigger. When theclosure trigger 3512 is in the unactuated position, the safety button iscontained in the handle assembly 3500 where the clinician cannot readilyaccess it and move it between a safety position preventing actuation ofthe firing trigger and a firing position wherein the firing trigger maybe fired. As the clinician depresses the closure trigger, the safetybutton and the firing trigger pivot down wherein they can then bemanipulated by the clinician.

In at least one form, the longitudinally movable drive member 3540 mayhave a rack of teeth formed thereon for meshing engagement with acorresponding drive gear arrangement (not shown) that interfaces withthe motor. Further details regarding those features may be found in U.S.Patent Application Publication No. 2015/0272575. In at least onearrangement, however, the longitudinally movable drive member isinsulated to protect it from inadvertent RF energy. At least one formalso includes a manually-actuatable “bailout” assembly that isconfigured to enable the clinician to manually retract thelongitudinally movable drive member should the motor 3505 becomedisabled. The bailout assembly may include a lever or bailout handleassembly that is stored within the handle assembly 3500 under areleasable door 3550. The lever may be configured to be manually pivotedinto ratcheting engagement with the teeth in the drive member. Thus, theclinician can manually retract the drive member 3540 by using thebailout handle assembly to ratchet the drive member in the proximaldirection “PD.” U.S. Pat. No. 8,608,045, entitled POWERED SURGICALCUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM,the entire disclosure of which is hereby incorporated herein byreference, discloses bailout arrangements and other components,arrangements and systems that may also be employed with any one of thevarious interchangeable surgical tool assemblies disclosed herein.

As shown in FIG. 22, in at least one arrangement, the interchangeablesurgical tool assembly 3600 includes a tool frame assembly 3610 thatcomprises a tool chassis that operably supports a nozzle assembly 3612thereon. As further discussed in detail in U.S. patent application Ser.No. 15/635,631, entitled SURGICAL INSTRUMENT WITH AXIALLY MOVABLECLOSURE MEMBER, which is hereby incorporated herein by reference in itsentirety, the tool chassis and nozzle assembly 3612 facilitate rotationof the surgical end effector 3602 about a shaft axis SA relative to thetool chassis. Such rotational travel is represented by arrow R in FIG.22. The interchangeable surgical tool assembly 3600 includes a spineassembly 3630 (see FIGS. 3 and 24) that operably supports the proximalclosure tube 3622 and is coupled to the surgical end effector 3602. Invarious circumstances, for ease of assembly, the spine assembly 3630 maybe fabricated from an upper spine segment and a lower spine segment thatare interconnected together by snap features, adhesive, welding, etc. Inassembled form, the spine assembly 3630 includes a proximal end that isrotatably supported in the tool chassis. In one arrangement, forexample, the proximal end of the spine assembly 3630 is attached to aspine bearing (not shown) that is configured to be supported within thetool chassis. Such arrangement facilitates rotatable attachment of thespine assembly 3630 to the tool chassis such that the spine assembly maybe selectively rotated about a shaft axis SA relative to the toolchassis.

In the illustrated aspect, the interchangeable surgical tool assembly3600 includes a surgical end effector 3602 that comprises a first jaw3604 and a second jaw 3608. In one arrangement, the first jaw comprisesan elongated channel 3614 that is configured to operably support aconventional (mechanical) surgical staple/fastener cartridge 304 (FIG.4) or a radio frequency (RF) cartridge 3606 (FIGS. 22 and 23) therein.The second jaw 3608 comprises an anvil 3616 that is pivotally supportedrelative to the elongated channel 3614. The anvil 3616 may beselectively moved toward and away from a surgical cartridge supported inthe elongated channel 3614 between open and closed positions byactuating the closure drive system 3510. In the illustrated arrangement,the anvil 3616 is pivotally supported on a proximal end portion of theelongated channel 3614 for selective pivotal travel about a pivot axisthat is transverse to the shaft axis SA. Actuation of the closure drivesystem 3510 may result in the distal axial movement of a proximalclosure member or proximal closure tube 3622 that is attached to anarticulation connector 3618. Actuation of the proximal closure tube 3622will result in the distal travel of the distal closure tube segment 3620to ultimately apply a closing motion to the anvil 3616.

In at least one arrangement, RF energy is supplied to the surgical toolassembly 3600 by a conventional RF generator 3400 through a supply lead3402. In at least one arrangement, the supply lead 3402 includes a maleplug assembly 3406 that is configured to be plugged into correspondingfemale connectors 3410 that are attached to a segmented RF circuit 3656on the an onboard circuit board 3654. See FIG. 25. Such arrangementfacilitates rotational travel of the shaft and end effector 3602 aboutthe shaft axis SA relative to the tool chassis by rotating the nozzleassembly 3612 without winding up the supply lead 3402 from the generator3400. An onboard on/off power switch 3420 is supported on the latchassembly 3624 and tool chassis for turning the RF generator on and off.When the tool assembly 3600 is operably coupled to the handle assembly3500 or robotic system, the onboard segmented RF circuit 3656communicates with the microprocessor 3560 through the connectors 3668and, in some arrangements, a housing connector (not shown). As shown inFIG. 22, the handle assembly 3500 may also include a display screen 3430for viewing information about the progress of sealing, stapling, knifelocation, status of the cartridge, tissue, temperature, etc. As can alsobe seen FIG. 25, the slip ring assembly 3652 includes a proximalconnector 3666 that interfaces with a distal connector 3658 thatincludes a flexible shaft circuit strip or assembly 3646 that mayinclude a plurality of narrow electrical conductors 3662 for staplingrelated activities and wider electrical conductors 3664 used for RFpurposes. As shown in FIGS. 24 and 25, the flexible shaft circuit strip3646 is centrally supported between the laminated plates or bars 3636that form the knife bar 3626. Such arrangement facilitates sufficientflexing of the knife bar 3626 and flexible shaft circuit strip 3646during articulation of the end effector 3602 while remainingsufficiently stiff so as to enable the knife member 3628 to be distallyadvanced through the clamped tissue.

In at least one arrangement, the elongated channel 3614 includes achannel circuit 3642 supported in a recess that extends from theproximal end of the elongated channel 3614 to a distal location in thebottom portion of the elongated channel 3614. The channel circuit 3642includes a proximal contact portion that contacts a distal contactportion 3644 of the flexible shaft circuit strip 3646 for electricalcontact therewith. In at least one arrangement, the distal end of thechannel circuit 3642 is received within a corresponding wall recessformed in one of the walls of the elongated channel 3614 and is foldedover and attached to an upper edge of the elongated channel 3614 wall. Aseries of corresponding exposed contacts are provided in the distal endof the channel circuit 3642. Correspondingly, the cartridge 3606 caninclude a flexible cartridge circuit that is attached to a distalmicro-chip and is affixed to the distal end portion of the body of thecartridge 3606. An end of the flexible cartridge circuit can be foldedover the edge of the deck surface of the cartridge 3606 and includesexposed contacts configured to make electrical contact with the exposedcontacts of the channel circuit 3642. Thus, when the RF cartridge 3606is installed in the elongated channel 3614, the electrodes as well asthe distal micro-chip of the RF cartridge 3606 are powered andcommunicate with the onboard circuit board 3654 through contact betweenthe flexible cartridge circuit, the flexible channel circuit 3642, theflexible shaft circuit 3646, and the slip ring assembly 3652. Furtherdetails regarding the RF cartridges 3606 and the corresponding circuitryand sensor arrangements of the surgical instrument 10 that communicateand/or interact with the RF cartridges 3606 can be found in U.S. patentapplication Ser. No. 15/636,096, entitled SURGICAL SYSTEM COUPLABLE WITHSTAPLE CARTRIDGE AND RADIO FREQUENCY CARTRIDGE, AND METHOD OF USINGSAME, which is hereby incorporated herein by reference in its entirety.

FIG. 26 illustrates a logic flow diagram of a process 6000 ofdetermining when to initiate a low power shutdown of the surgicalinstrument 10 (FIGS. 1, 22) as executed by the controller 1104 (FIG. 10)according to one aspect of this disclosure. In various aspects, thesurgical instrument 10 can be configured to execute processes, such asprocess 6000, that are configured to monitor the various operationalstates of the surgical instrument 10 and then initiate a low power orpower shutdown mode according to those determined operational states.Such functionality can be useful in order to, e.g., reduce the powerdrawn from the energy source 2512 (FIG. 14) when the process 6000determines that the operational states of the surgical instrument 10have been completed, which allows the surgical instrument 10 togenerally conserve energy. In the following description of the process4000, reference should also be made to FIGS. 3, 10, and 16-23. As usedherein, the term “knife” can collectively refer to the knife bar 280(also referred to as the firing bar 172), cutting edge 182, and otherrelated components that are advanced distally to transect tissue.

Accordingly, the controller 1104 checks 6002 the knife state of thesurgical instrument 10. The firing or knife state is an operationalstate of the surgical instrument 10 wherein the knife bar 280 is beingtranslated to transect tissue captured at the end effector 2300. Thecontroller 1104 can determine whether the knife bar 280 is being firedby, e.g., sensing the position of a component of the knife system via aposition sensor 1112, detecting whether a voltage is being applied tothe motor 1120, detecting the position of the firing trigger, detectingwhether the closure drive system 3510 has been activated, detectingrelative positions of the jaws 3604, 3608 (or the anvil 3616 and thecartridge 3606) of the end effector 2300, or by combinations thereof. Inone general aspect, if the controller 1104 detects that the firingsystem for the knife has been activated and the end effector 2300 isclamped, then the process 5000 determines that the surgical instrument10 is in a firing state.

The controller 1104 can detect that the firing system for the knife hasbeen activated in a variety of different ways. In one aspect, thecontroller 1104 is configured to directly sense the translation of theknife bar 280. In this aspect, the displacement member 1111 tracked bythe position sensor 1112 represents the knife bar 280. In other aspects,the controller 1104 is configured to indirectly sense the translation ofthe knife bar 280 by instead sensing the translation of a component thatis coupled to the knife bar 280. In these aspects, the displacementmember 1111 tracked by the position sensor 1112 represents thelongitudinally movable drive member 120 (FIG. 2), the I-beam 178 (FIG.4), or another component of the knife system or the firing drive system80. In any of these aspects, when the position sensor 1112 detects thatthe displacement member 1111 is advancing from a first (i.e., proximalor home) position to a second (i.e., distal) position, the controller1104 can thereby determine that the knife bar 280 is being fired. Inanother aspect, the controller 1104 can be communicably coupled to acurrent sensor 2536 (FIG. 14) that is configured to detect when themotor 2504 is drawing power from the energy source 2512. When thecurrent sensor 2536 detects that the motor 2504 is drawing power (i.e.,a voltage is being applied to the motor 2504), the controller 1104 canthereby determine that the knife bar 280 is being fired because themotor 2504 drives the knife bar 280 when a voltage is applied thereto.In yet another aspect, the other sensor(s) 1118 can include a firingtrigger sensor configured to determine when the firing trigger (notshown) has been actuated. As the firing trigger causes the knife systemto fire, detecting whether the firing trigger has been actuated thusserves as a proxy for determining the firing state of the surgicalinstrument 10. The firing trigger sensor can include, e.g., a positionsensor configured to detect the position of the firing trigger relativeto the handle assembly 3500. Various other aspects include combinationsof the aforementioned sensor arrangements and/or various additionalsensors configured to detect when the knife system or the firing drivesystem 80 is activated.

The controller 1104 can detect that the end effector 2300 is clamped ina variety of different ways. In one aspect, the other sensor(s) 1118 caninclude a closure trigger sensor configured to determine when theclosure trigger 3512 has been actuated. As the closure trigger 3512causes the closure drive system 3510 to be activated, detecting whetherthe closure trigger 3512 has been actuated thus serves as a proxy fordetermining whether the end effector 2300 is in a clamped or unclampedposition. The closure trigger sensor can include, e.g., a positionsensor configured to detect the position of the closure trigger 3512relative to the handle assembly 3500. Other aspects can include a firingtrigger sensor or a firing button sensor for detecting the actuation ofthe firing controls. The other sensor(s) 1118 can further include aclosure drive system sensor configured to detect the activation of theclosure drive system 3510. For example, the other sensor(s) 1118 caninclude a sensor configured to measure forces exerted on the anvil 3616by the closure tube 3620 or a sensor configured to measure the relativeposition of the closure tube 3620 or another movable component of theclosure drive system that translates between a first position and asecond position to effect the closure of the end effector 2300. Theother sensor(s) 1118 can further include a jaw sensor configured todetermine whether the jaws 3604, 3608 of the end effector 2300 are in aclamped or unclamped position. For example, the other sensor(s) 1118 caninclude a sensor configured to detect a distance between the first jaw3604 and the second jaw 3608, a pressure sensor disposed on at least oneof the first jaw 3604 and/or the second jaw 3608 that is configured todetect when the end effector 2300 is clamped on an object (e.g.,tissue), or an impedance sensor configured to detect impedance of tissuelocated between the first jaw 3604 and the second jaw 3608.

The process 6000 executed by the controller 1104 then determines 6004whether the knife bar 280 is firing according to whether the process6000 determined that the knife state is active or inactive. In onespecific example, the surgical instrument 10 includes a firing triggersensor, as described above, and a jaw sensor, as describe above. If thecontroller 1104 detects that the firing trigger has been actuated andthat the jaws 3604, 3608 of the end effector 2300 are clamped via theaforementioned sensors, then the process 6000 determines 6004 that thesurgical instrument 10 is in a firing state, i.e., the knife bar 280 isbeing advanced to transect tissue. Various other aspects can include thesensor arrangements described above either in isolation or in othercombinations to determine whether the surgical instrument 10 is in afiring state. Further information regarding various sensor arrangementscan be found in U.S. patent application Ser. No. 15/628,175, entitledTECHNIQUES FOR ADAPTIVE CONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLINGAND CUTTING INSTRUMENT, which is hereby incorporated herein by referencein its entirety.

If the knife bar 280 is firing, then the process 6000 continues alongthe YES branch and proceeds to determine 6006 whether the knife bar 280is at the home position. The position of the knife bar 280 can be senseddirectly or indirectly, as described above. Regardless of whether thedisplacement member 1111 represents the knife bar 280, thelongitudinally movable drive member 120 (FIG. 2), or another suchlongitudinally movable component of the knife system or the firing drivesystem 80, the process 6000 can determine 6004 whether the knife bar 280is at the home position by detecting the position of the displacementmember 1111 relative to its initial position. Even if the displacementmember 1111 does not directly represent the knife bar 280, the positionof the displacement member 1111 corresponds to the position of the knifebar 280 because they are operably coupled together. In other words,translation of, e.g., the longitudinally movable drive member 120 causesa corresponding translation in the knife bar 280, as described above.Therefore, when the displacement 1111 is located at its first or unfiredposition, the knife bar 280 is likewise located at its unfired position.The controller 1104 can be configured to retrieve the home position ofthe displacement member 1111 from, e.g., the memory 1106, and thencompare the current position of the displacement member 1111 to theretrieved home position of the displacement member 1111 to determinewhether the displacement member 1111 is in the home position.

If the knife bar 280 is not located at its home position, then theprocess 6000 continues along the NO branch and proceeds to allow theknife bar 280 to continue 6008 transection (i.e., firing or cuttingtissue). After allowing the knife bar 280 to continue 6008 transection,the process 6000 then loops back and re-determines 6006 whether theknife bar 280 is at the home position. In various aspects, the process6000 can continue this loop continuously until it determines 6006 thatthe knife bar 280 is at the home position. The step of allowing theknife bar 280 to continue 6008 transection can include, e.g., a timedelay prior to re-determining 6006 whether the knife bar 280 is locatedat the home position.

Once the process 6000 determines 6006 that the knife bar 280 is at thehome position, the process 6000 proceeds along the YES branch and thenchecks 6010 the articulation state of the surgical instrument 10. In oneaspect, the process 6000 likewise proceeds to check 6010 thearticulation state of the surgical instrument 10 if the process 6000proceeded along the NO branch from the step of determining 6004 whetherthe knife bar 280 was firing. In another aspect, the process 6000determines 6006 whether the knife bar 280 is at the home positionregardless of whether or not the knife bar 280 is firing, as determined6004 by the process 6000. In this aspect, the process 6000 only proceedsto check 6010 the articulation state once the process 6000 determines6006 that the knife bar 280 is at the home position. In other words, inthis aspect the process 6000 only continues when the knife bar 280 is atthe home position.

The articulation state corresponds to whether the end effector 2300 isarticulating or is in a static position. When the end effector 2300 isarticulating, it can be said to be in an active operational state. Whenthe end effector 2300 is not articulating, it can be said to be in aninactive operational state. The controller 1104 can determine thearticulation state by, e.g., sensing a position of a component in thearticulation system 2800 via a position sensor 1112, sensing an angularposition of the end effector 2300, or combinations thereof. In oneaspect, the displacement member 1111 tracked by the position sensor 1112represents the articulation driver 230 or another component of thearticulation system 2800 or the firing drive system 80. In anotheraspect, the surgical instrument 10 can include an articulation sensorarrangement, which in turn can include a position sensor and a magnetthat is operatively coupled to the articulation joint 2270 such that itrotates in a manner consistent with the rotation of the articulationjoint 2270. As described above, as the magnet rotates, the magneticsensing elements of the position sensor determine the magnet's absoluteangular position, which then corresponds to the angular position (i.e.,articulation position) of the end effector 2300.

After checking 6010 the articulation state of the surgical instrument10, the process 6000 then determines 6012 whether the end effector 2300is at the home position. In one aspect, the process 6000 determineswhether the end effector 2300 is in the home position by determining theposition of the displacement member 1111 (which may correspond to thelongitudinally movable driver member 3540, the articulation driver 230,or another movable component in the articulation system 2800) relativeto the proximal and distal limits between which the displacement member1111 is translated. Because the articulation of the end effector 2300 isdriven by the displacement member 1111, the limits of the translationrange of the displacement member 1111 correspond to the limits of thearticulation range of the end effector 2300. Thus, the proximal positionof the displacement member 1111 corresponds to a first limit of thearticulation range of the end effector 2300 and, accordingly, the distalposition of the displacement member 1111 corresponds to a second limitof the articulation range of the end effector 2300. Therefore, theprocess 6000 executed by the controller 1104 can determine 6012 whetherthe end effector 2300 is at its home position according the position ofthe displacement member 1111 relative to the limits of the displacementmember's 1111 translation range. The home position of the end effector2300 can correspond to one of the limits of its articulation range, amidpoint between the limits of its articulation range, or any otherposition therebetween. In one aspect, the home position of the endeffector 2300 corresponds to the position in its articulation rangewhere the end effector 2300 is aligned with the longitudinal axis of theshaft of the surgical instrument 10. The proximal and distal positionsof the displacement member 1111 can be, e.g., stored in the memory 1106and retrieved by the controller 1104 to calculate the relative angularposition of the end effector 2300. In another aspect, the process 4000determines the relative articulation position of the end effector 2300by directly detecting the angle at which the articulation joint 2270and/or end effector 2300 is oriented by, e.g., an articulation sensorarrangement. The detected articulation angle of the end effector 2300can be compared to the limits of its articulation range, which can be,e.g., stored in the memory 1106 and retrieved by the controller 1104 tocalculate the relative position of the end effector 2300.

If the end effector 2300 is not located at its home position, then theprocess 6000 continues along the NO branch and proceeds to allow the endeffector 2300 to continue 6014 articulating. After allowing the endeffector 2300 to continue 6014 articulating, the process 6000 then loopsback and re-determines 6012 whether the end effector 2300 is at the homeposition. In various aspects, the process 6000 can continue this loopcontinuously until it determines 6012 that the angular position of theend effector 2300 is the home position. The step of allowing the endeffector 2300 to continue 6014 articulating can include, e.g., a timedelay prior to re-determining 6012 whether the end effector 2300 islocated at the home position.

If the process 6000 determines 6012 that the end effector 2300 islocated at the home position, then the process 6000 continues along theYES branch and initiates 6016 a power shutdown mode. The power shutdownmode causes the controller 1104 to deactivate one or more processes thatare being executed thereby and/or deactivate various components of thesurgical instrument 10 that are drawing power from power sources (e.g.,energy source 2512), such as the position sensor 1112, the othersensor(s) 1118, the display screen 3430 (FIG. 23), and the motor 2504(FIG. 14). In one aspect depicted in FIG. 27, the controller 1104 causesthe display screen 6030 to display an image 6032 to visually indicate tothe clinician that the surgical instrument 10 has entered the powershutdown mode. The image 6032 can be displayed indefinitely or for onlya set period of time. In sum, the process 6000 as executed by thecontroller 1104 causes the surgical instrument 10 to enter a low powermode or power shutdown mode when the process 6000 detects that the knifebar 280 and the end effector 2300 are both in their respective homepositions. In one aspect, the process 6000 includes an additional stepof waiting for a variable or predetermined period of time prior toinitiating 6016 the power shutdown mode. In other words, in some aspectsthe process 6000 only initiates 6016 the low power mode if the knife andthe end effector 2300 have been located in their respective homepositions for a period of time exceeding a particular thresholdduration.

In various aspects, the surgical instrument 10 is configured toreactivate to the full power mode from the power shutdown mode when aclinician inputs a command via a capacitive screen (e.g., display screen3430) or when a motion sensor detects that the surgical instrument 10 isshaken or otherwise manipulated.

The functions or processes for controlling a surgical instrument toinitiate a power shutdown mode according to the operational state of thesurgical instrument described herein may be executed by any of theprocessing circuits described herein, such as the control circuit 700described in connection with FIGS. 5A-6, the circuits 800, 810, 820described in FIGS. 7-9, the controller 1104 described in connection withFIGS. 10 and 12, and/or the control circuit 2510 described in FIG. 14.

Aspects of the motorized surgical instrument may be practiced withoutthe specific details disclosed herein. Some aspects have been shown asblock diagrams rather than detail. Parts of this disclosure may bepresented in terms of instructions that operate on data stored in acomputer memory. An algorithm refers to a self-consistent sequence ofsteps leading to a desired result, where a “step” refers to amanipulation of physical quantities which may take the form ofelectrical or magnetic signals capable of being stored, transferred,combined, compared, and otherwise manipulated. These signals may bereferred to as bits, values, elements, symbols, characters, terms,numbers. These and similar terms may be associated with the appropriatephysical quantities and are merely convenient labels applied to thesequantities.

Generally, aspects described herein which can be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or any combination thereof can be viewed as being composed ofvarious types of “electrical circuitry.” Consequently, “electricalcircuitry” includes electrical circuitry having at least one discreteelectrical circuit, electrical circuitry having at least one integratedcircuit, electrical circuitry having at least one application specificintegrated circuit, electrical circuitry forming a general purposecomputing device configured by a computer program (e.g., a generalpurpose computer or processor configured by a computer program which atleast partially carries out processes and/or devices described herein,electrical circuitry forming a memory device (e.g., forms of randomaccess memory), and/or electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, or optical-electricalequipment). These aspects may be implemented in analog or digital form,or combinations thereof.

The foregoing description has set forth aspects of devices and/orprocesses via the use of block diagrams, flowcharts, and/or examples,which may contain one or more functions and/or operations. Each functionand/or operation within such block diagrams, flowcharts, or examples canbe implemented, individually and/or collectively, by a wide range ofhardware, software, firmware, or virtually any combination thereof. Inone aspect, several portions of the subject matter described herein maybe implemented via Application Specific Integrated Circuits (ASICs),Field Programmable Gate Arrays (FPGAs), digital signal processors(DSPs), Programmable Logic Devices (PLDs), circuits, registers and/orsoftware components, e.g., programs, subroutines, logic and/orcombinations of hardware and software components. logic gates, or otherintegrated formats. Some aspects disclosed herein, in whole or in part,can be equivalently implemented in integrated circuits, as one or morecomputer programs running on one or more computers (e.g., as one or moreprograms running on one or more computer systems), as one or moreprograms running on one or more processors (e.g., as one or moreprograms running on one or more microprocessors), as firmware, or asvirtually any combination thereof, and that designing the circuitryand/or writing the code for the software and or firmware would be wellwithin the skill of one of skill in the art in light of this disclosure.

The mechanisms of the disclosed subject matter are capable of beingdistributed as a program product in a variety of forms, and that anillustrative aspect of the subject matter described herein appliesregardless of the particular type of signal bearing medium used toactually carry out the distribution. Examples of a signal bearing mediuminclude the following: a recordable type medium such as a floppy disk, ahard disk drive, a Compact Disc (CD), a Digital Video Disk (DVD), adigital tape, a computer memory, etc.; and a transmission type mediumsuch as a digital and/or an analog communication medium (e.g., a fiberoptic cable, a waveguide, a wired communications link, a wirelesscommunication link (e.g., transmitter, receiver, transmission logic,reception logic, etc.).

The foregoing description of these aspects has been presented forpurposes of illustration and description. It is not intended to beexhaustive or limiting to the precise form disclosed. Modifications orvariations are possible in light of the above teachings. These aspectswere chosen and described in order to illustrate principles andpractical application to thereby enable one of ordinary skill in the artto utilize the aspects and with modifications as are suited to theparticular use contemplated. It is intended that the claims submittedherewith define the overall scope.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1. A surgical instrument comprising: an end effector pivotablebetween an unarticulated position and an articulated position; adisplacement member coupled to the end effector, the displacement membermovable between a first position and a second position to drive the endeffector between the unarticulated position and the articulatedposition; a knife bar movable between a unfired position and a firedposition; a control circuit configured to: determine a firing stateaccording to whether the knife bar is moving between the unfiredposition and the fired position; determine an articulation stateaccording to whether the displacement member is moving between the firstposition and the second position; and initiate a power shutdown modeaccording to the firing state and the articulation state.

Example 2. The surgical instrument of Example 1, wherein the controlcircuit is configured to not initiate the power shutdown mode unless theknife bar is in the unfired position.

Example 3. The surgical instrument of Example 1 or Example 2, whereinthe control circuit is configured to not initiate the power shutdownmode unless the displacement member is in the first position.

Example 4. The surgical instrument of at least one of Example 1 throughExample 3, further comprising: a firing trigger coupled to the knifebar, the firing trigger configured to drive the knife bar between theunfired position and the fired position; wherein the control circuit isconfigured to determine whether the knife bar is moving according to aposition of the firing trigger.

Example 5. The surgical instrument of at least one of Example 1 throughExample 4, further comprising: a motor coupled to the knife bar, themotor configured to drive the knife bar between the unfired position andthe fired position; wherein the control circuit is configured todetermine whether the knife bar is moving according to a voltage of themotor.

Example 6. The surgical instrument of at least one of Example 1 throughExample 5, further comprising: a sensor configured to detect a positionof the knife bar and provide a signal indicative thereof; wherein thecontrol circuit is configured to determine whether the knife bar ismoving according to the signal.

Example 7. The surgical instrument of at least one of Example 1 throughExample 6, further comprising: a sensor configured to detect a positionof the displacement member and provide a signal indicative thereof;wherein the control circuit is configured to determine whether thedisplacement member is moving according to the signal.

Example 8. A surgical instrument comprising: an end effector pivotablefrom an articulation home position; a knife bar movable from a knifehome position; and a control circuit configured to: determine whetherthe knife bar is moving; determine whether the end effector is moving;and initiate a power shutdown mode upon the knife bar and the endeffector not moving.

Example 9. The surgical instrument of Example 8, wherein the controlcircuit is configured to not initiate the power shutdown mode unless theknife bar is in the knife home position.

Example 10. The surgical instrument of Example 8 or Example 9, whereinthe control circuit is configured to not initiate the power shutdownmode unless the end effector is in the articulation home position.

Example 11. The surgical instrument of at least one of Example 8 throughExample 10, further comprising: a firing trigger coupled to the knifebar, the firing trigger configured to drive the knife bar from the knifehome position; wherein the control circuit is configured to determinewhether the knife bar is moving according to a position of the firingtrigger.

Example 12. The surgical instrument of at least one of Example 8 throughExample 11, further comprising: a motor coupled to the knife bar, themotor configured to drive the knife bar from the knife home position;wherein the control circuit is configured to determine whether the knifebar is moving according to a voltage of the motor.

Example 13. The surgical instrument of at least one of Example 8 throughExample 12, further comprising: a sensor configured to detect a positionof the knife bar and provide a signal indicative thereof; wherein thecontrol circuit is configured to determine whether the knife bar ismoving according to the signal.

Example 14. The surgical instrument of at least one of Example 8 throughExample 13, further comprising: a sensor configured to detect a positionof the end effector and provide a signal indicative thereof; wherein thecontrol circuit is configured to determine whether the end effector ismoving according to the signal.

Example 15. A method of controlling a surgical instrument comprising anend effector, a displacement member coupled to the end effector, thedisplacement member movable between a first position and a secondposition, and a knife bar movable between a unfired position and a firedposition, the method comprising: determining a firing state according towhether the knife bar is moving between the unfired position and thefired position; determining an articulation state according to whetherthe displacement member is moving between the first position and thesecond position; and initiating a power shutdown mode according to thefiring state and the articulation state.

Example 16. The method of Example 15, wherein the power shutdown mode isnot initiated unless the knife bar is in the unfired position.

Example 17. The method of Example 15 or Example 16, wherein the powershutdown mode is not initiated unless the displacement member is in thefirst position.

Example 18. The method of at least one of Example 15 through Example 17,further comprising determining whether the knife bar is moving accordingto a position of a firing trigger coupled to the knife bar.

Example 19. The method of at least one of Example 15 through Example 18,further comprising determining whether the knife bar is moving accordingto a voltage of a motor coupled to the knife bar.

Example 20. The method of at least one of Example 15 through Example 19,further comprising determining whether the knife bar is moving accordingto a sensor configured to detect a position of the knife bar.

Example 21. The method of at least one of Example 15 through Example 20,further comprising determining whether the displacement member is movingaccording to a sensor configured to detect a position of thedisplacement member.

The invention claimed is:
 1. A surgical instrument comprising: an endeffector pivotable between an unarticulated position and an articulatedposition, the unarticulated position of the end-effector defining anend-effector home position; a displacement member coupled to the endeffector, the displacement member movable between a first position and asecond position to drive the end effector between the unarticulatedposition and the articulated position; a knife bar movable between aknife bar home position and a knife bar fired position; and a controlcircuit configured to conserve energy after completion of operationalstates of the surgical instrument, wherein to conserve energy thecontrol circuit is configured to: determine that the knife bar is in theknife bar home position; determine that the end-effector is in theend-effector home position; and initiate a power shutdown mode based onthe determination that the knife bar is in the knife bar home positionand the end-effector is in the end-effector home position; wherein thecontrol circuit is further configured to retrieve the home position ofthe knife bar and the end-effector from a memory and compare a currentposition of the knife bar and the end-effector to the retrieved homeposition of the knife bar and the end-effector; and wherein the controlcircuit is further configured to override the power shutdown mode inresponse to a received command.
 2. The surgical instrument of claim 1,further comprising: a firing trigger coupled to the knife bar, thefiring trigger configured to drive the knife bar between the knife barhome position and the knife bar fired position; wherein the controlcircuit is configured to determine whether the knife bar is movingaccording to a position of the firing trigger.
 3. The surgicalinstrument of claim 1, further comprising: a motor coupled to the knifebar, the motor configured to drive the knife bar between the knife barhome position and the knife bar fired position; wherein the controlcircuit is configured to determine whether the knife bar is movingaccording to a voltage of the motor.
 4. The surgical instrument of claim1, further comprising: a sensor configured to detect a position of theknife bar and provide a signal indicative thereof; wherein the controlcircuit is configured to determine whether the knife bar is movingaccording to the signal.
 5. The surgical instrument of claim 1, furthercomprising: a sensor configured to detect a position of the displacementmember and provide a signal indicative thereof; wherein the controlcircuit is configured to determine whether the displacement member ismoving according to the signal.
 6. The surgical instrument of claim 1,further comprising a motion sensor configured to detect when thesurgical instrument physically manipulated, and wherein the receivedcommand comprises a physical manipulation of the surgical instrument. 7.The surgical instrument of claim 1, further comprising a user interfacecoupled to the control circuit, and wherein the received commandcomprises an input received via the user interface.
 8. A surgicalinstrument comprising: an end effector pivotable between anunarticulated position and an articulated position, the unarticulatedposition of the end-effector defining an end-effector home position; adisplacement member coupled to the end effector, the displacement membermovable between a first position and a second position to drive the endeffector between the unarticulated position and the articulatedposition; a knife bar movable between a knife bar home position and aknife bar fired position; a control circuit configured to conserveenergy after completion of operational states of the surgicalinstrument, wherein to conserve energy the control circuit is configuredto: retrieve the home position of the knife bar from a memory; determinethat the knife bar is in the knife bar home position by comparing acurrent position of the knife bar to the retrieved home position of theknife bar; determine that the end-effector is in the end-effector homeposition; and initiate a power shutdown mode based on the determinationthat the knife bar is in the knife bar home position and end-effector isin the end-effector home position; and wherein the control circuit isfurther configured to override the power shutdown mode in response to areceived command.
 9. A method of conserving energy when operationalstates of a surgical instrument have been completed, wherein thesurgical instrument comprises an end effector, a displacement membercoupled to the end effector, the displacement member movable between afirst position and a second position, and a knife bar movable between ahome position and a fired position, the method comprising: retrievingthe home position of the knife bar from a memory; determining a currentposition of the knife bar based, at least in part, on a signal receivedfrom a position sensor corresponding to the current position of theknife bar; determining a firing state of the knife bar based, at leastin part, on a comparison of the current position of the knife bar to theretrieved home position of the knife bar; determining an articulationstate according to whether the displacement member is moving between thefirst position and the second position; initiating a power shutdown modeaccording to the firing state and the articulation state; and overridingthe power shutdown mode in response to a received command; wherein thepower shutdown mode is initiated only in the home position of the knifebar.
 10. The method of claim 9, further comprising determining whetherthe knife bar is moving according to a position of a firing triggercoupled to the knife bar.
 11. The method of claim 9, further comprisingdetermining whether the knife bar is moving according to a voltage of amotor coupled to the knife bar.
 12. The method of claim 9, furthercomprising determining whether the knife bar is moving according to theposition sensor configured to detect a position of the knife bar. 13.The method of claim 9, further comprising determining whether thedisplacement member is moving according to a sensor configured to detecta position of the displacement member.
 14. A method of reducing powerdrawn from an energy source of a surgical instrument, wherein thesurgical instrument comprises an end effector pivotable between anunarticulated position and an articulated position, a displacementmember coupled to the end effector, the displacement member movablebetween a first position and a second position to drive the end effectorbetween the unarticulated position and the articulated position, a knifebar movable between a home position and a fired position, and a sensorcommunicably coupled to a control circuit, the method comprising:detecting, via the sensor, a position of the knife bar; determining, viathe control circuit, that the knife bar is at the home position based ona signal received from the sensor; detecting, via the sensor, anarticulation state of the end effector; determining, via the controlcircuit, that the end effector is at the unarticulated position based ona second signal received from the sensor; and initiating, via thecontrol circuit, a power shutdown mode of the surgical instrument basedon the determination that the knife bar is at the home position and thedetermination that the end effector is at the unarticulated position,wherein the power shutdown mode causes deactivation of a component thatis drawing power from the energy source.